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655-705 Level|   Assumption|            
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Rabbits were introduced to Tambor Island in the nineteenth century. Overgrazing by the enormous rabbit population now menaces the island's agriculture. The government proposes to reduce the population by using a virus that has caused devastating epidemics in rabbit populations elsewhere. There is, however, a small chance that the virus will infect the bilby, an endangered native herbivore. The government's plan, therefore, may serve the interests of agriculture but will clearly increase the threat to native wildlife.

The argument above assumes which of the following?

A) There is less chance that the virus will infect domestic animals on Tambor than that it will infect wild animals of species native to the island.
B) Overgrazing by rabbits does not pose the most significant current threat to the bilby.
C) There is at least one alternative means of reducing the rabbit population that would not involve any threat to the bilby.
D) There are no species of animals on the island that prey on the rabbits.
E) The virus that the government proposes to use has been successfully used elsewhere to control populations of rabbits.

Here are my views--

Option (A)--Irrerelevant.Even if it infects domestic animals less and wil animals more it is not an assumption on which the conclusion is stated.Out
Option (B)--Good.Keep it.
Option ©--So what if there is.We need an assumption whereas this states another remedy.Out of Scope.Out.
Option (D)--Even if there is any its not an assumption used in the argument.Out of Scope.Out.
Option (E)--Its already been stated in the argument and thus is not an assumption.Out.

OA is 'B'.
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B for.me as well ...what's the OA

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Conclusion : The government's plan might be successful to reduce the population of Rabbits but it will clearly increase the threat to native wildlife.

Introduction of Rabits >> Overgrazing
Overgrazing >> Impact on native wildlife ??
if there is any impact , then Overgrazing would have increased the threat to native wildlife not the government's plan.
Hence the assumption is that there is no other factor which will cause negative impact on native wildlife apart from the government's plan.

Ans : B
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chetan2u

Can you please explain this ?
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Hello,

The question states that:
1) Someone put rabbit in an region
So 2) Overgrazing by rabbits are threatening agriculture

3) Government people think: let's kill the rabbit introducing a virus
But 4) This virus can also threat the bilby, a native animal

Conclusion: the government plan will not only threat rabbit but also the bilby ('clearly')

What if the bilbies have been already threatening by the rabbits? So, the problem would be not the government's virus, but the rabbits themselves.

Thus, the author, in order to make his/her conclusion, assumes that the bilby is not currently threatened by rabbits.

Best,
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Rabbits were introduced to Tambor Island in the nineteenth century. Overgrazing by the enormous rabbit population now menaces the island's agriculture. The government proposes to reduce the population by using a virus that has caused devastating epidemics in rabbit populations elsewhere. There is, however, a small chance that the virus will infect the bilby, an endangered native herbivore. The government's plan, therefore, may serve the interests of agriculture but will clearly increase the threat to native wildlife.

The argument above assumes which of the following?

A) There is less chance that the virus will infect domestic animals on Tambor than that it will infect wild animals of species native to the island.
B) Overgrazing by rabbits does not pose the most significant current threat to the bilby.
C) There is at least one alternative means of reducing the rabbit population that would not involve any threat to the bilby.
D) There are no species of animals on the island that prey on the rabbits.
E) The virus that the government proposes to use has been successfully used elsewhere to control populations of rabbits.


Hi VeritasKarishma, if you can please provide explanation on the above question and why B is the answer? Didn't quite get it.
Thanks a lot.
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s1lntz
Rabbits were introduced to Tambor Island in the nineteenth century. Overgrazing by the enormous rabbit population now menaces the island's agriculture. The government proposes to reduce the population by using a virus that has caused devastating epidemics in rabbit populations elsewhere. There is, however, a small chance that the virus will infect the bilby, an endangered native herbivore. The government's plan, therefore, may serve the interests of agriculture but will clearly increase the threat to native wildlife.

The argument above assumes which of the following?

A) There is less chance that the virus will infect domestic animals on Tambor than that it will infect wild animals of species native to the island.
B) Overgrazing by rabbits does not pose the most significant current threat to the bilby.
C) There is at least one alternative means of reducing the rabbit population that would not involve any threat to the bilby.
D) There are no species of animals on the island that prey on the rabbits.
E) The virus that the government proposes to use has been successfully used elsewhere to control populations of rabbits.

Overgrazing by rabbits is harming agriculture.
Plan is to introduce a virus that will reduce rabbit population.
There is a small chance that the virus will infect bilby (native wildlife) too.

Conclusion: Plan may help agriculture but will clearly INCREASE threat to native wildlife.

Our conclusion says that the threat to native wildlife will increase because of the introduction of virus. So whatever is the threat to native wildlife right now, it will increase by the introduction of the virus. What is our assumption here?


A) There is less chance that the virus will infect domestic animals on Tambor than that it will infect wild animals of species native to the island.
Irrelevant. Comparison with domestic animals are out of scope. We are talking about wildlife only.

B) Overgrazing by rabbits does not pose the most significant current threat to the bilby.
Correct. We are concluding that threat will increase. What if overgrazing is a huge threat right now which could affect the bilby population badly? Then introducing the virus may actually reduce the threat - after all, there is a small chance that the virus will affect bilby. Introducing the virus will eliminate the overgrazing threat and introduce a small chance that the virus could affect bilby. So it is possible that introducing the virus may decrease the overall threat to wildlife.

C) There is at least one alternative means of reducing the rabbit population that would not involve any threat to the bilby.
Irrelevant. We are discussing the merits/demerits of this plan.

D) There are no species of animals on the island that prey on the rabbits.
If there are some species that prey on the rabbit, introducing the virus may reduce their food supply. So the wildlife may suffer. Hence our conclusion becomes stronger, if anything.

E) The virus that the government proposes to use has been successfully used elsewhere to control populations of rabbits.
We don't know and it doesn't matter. The virus has caused epidemic in rabbit population and that's all.

Answer (B)
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Assumption-?

without looking at the choices, what can be the assumption for the argument-
1) herbivore cannot be vaccinated or protected against the virus.
2) If threat is INCREASING because of virus, the species are better with the existing system. And this system includes the overgrazing by enormous population of rabbit.
Ofcourse one-two more can be found but the above two will remain

point 2 is given by choice B..

lets see what other choices rae doing..

A) There is less chance that the virus will infect domestic animals on Tambor than that it will infect wild animals of species native to the island.
Out of scope. we are not interested in domestic animals here

B) Overgrazing by rabbits does not pose the most significant current threat to the bilby.
YEAH, point 2 above

C) There is at least one alternative means of reducing the rabbit population that would not involve any threat to the bilby.
The para is talking of a specific plan, so alternative mean will not effect the argument

D) There are no species of animals on the island that prey on the rabbits.
Again out of scope, we are talking of a specific case

E) The virus that the government proposes to use has been successfully used elsewhere to control populations of rabbits
Not necessary. it may be introduced in very small scale till now.
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VeritasKarishma
s1lntz
Rabbits were introduced to Tambor Island in the nineteenth century. Overgrazing by the enormous rabbit population now menaces the island's agriculture. The government proposes to reduce the population by using a virus that has caused devastating epidemics in rabbit populations elsewhere. There is, however, a small chance that the virus will infect the bilby, an endangered native herbivore. The government's plan, therefore, may serve the interests of agriculture but will clearly increase the threat to native wildlife.

The argument above assumes which of the following?

A) There is less chance that the virus will infect domestic animals on Tambor than that it will infect wild animals of species native to the island.
B) Overgrazing by rabbits does not pose the most significant current threat to the bilby.
C) There is at least one alternative means of reducing the rabbit population that would not involve any threat to the bilby.
D) There are no species of animals on the island that prey on the rabbits.
E) The virus that the government proposes to use has been successfully used elsewhere to control populations of rabbits.

Overgrazing by rabbits is harming agriculture.
Plan is to introduce a virus that will reduce rabbit population.
There is a small chance that the virus will infect bilby (native wildlife) too.

Conclusion: Plan may help agriculture but will clearly INCREASE threat to native wildlife.

Our conclusion says that the threat to native wildlife will increase because of the introduction of virus. So whatever is the threat to native wildlife right now, it will increase by the introduction of the virus. What is our assumption here?


A) There is less chance that the virus will infect domestic animals on Tambor than that it will infect wild animals of species native to the island.
Irrelevant. Comparison with domestic animals are out of scope. We are talking about wildlife only.

B) Overgrazing by rabbits does not pose the most significant current threat to the bilby.
Correct. We are concluding that threat will increase. What if overgrazing is a huge threat right now which could affect the bilby population badly? Then introducing the virus may actually reduce the threat - after all, there is a small chance that the virus will affect bilby. Introducing the virus will eliminate the overgrazing threat and introduce a small chance that the virus could affect bilby. So it is possible that introducing the virus may decrease the overall threat to wildlife.

C) There is at least one alternative means of reducing the rabbit population that would not involve any threat to the bilby.
Irrelevant. We are discussing the merits/demerits of this plan.

D) There are no species of animals on the island that prey on the rabbits.
If there are some species that prey on the rabbit, introducing the virus may reduce their food supply. So the wildlife may suffer. Hence our conclusion becomes stronger, if anything.

E) The virus that the government proposes to use has been successfully used elsewhere to control populations of rabbits.
We don't know and it doesn't matter. The virus has caused epidemic in rabbit population and that's all.

Answer (B)

I selected Answer A with the logic that domesticated animals fall into the category of "agriculture." Therefore, the risk to agriculture is low and has potential benefits while the risk to wildlife, which includes the Bilby that was discussed, is high. Would you mind explaining if there is something I am missing that makes this answer is incorrect?

Thank you!
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Bunuel, this is a Gmatprep question, can you tag? Thanks!
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Bunuel, this is a Gmatprep question, can you tag? Thanks!
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Added the tag. Thank you!
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VeritasKarishma
s1lntz
Rabbits were introduced to Tambor Island in the nineteenth century. Overgrazing by the enormous rabbit population now menaces the island's agriculture. The government proposes to reduce the population by using a virus that has caused devastating epidemics in rabbit populations elsewhere. There is, however, a small chance that the virus will infect the bilby, an endangered native herbivore. The government's plan, therefore, may serve the interests of agriculture but will clearly increase the threat to native wildlife.

The argument above assumes which of the following?

A) There is less chance that the virus will infect domestic animals on Tambor than that it will infect wild animals of species native to the island.
B) Overgrazing by rabbits does not pose the most significant current threat to the bilby.
C) There is at least one alternative means of reducing the rabbit population that would not involve any threat to the bilby.
D) There are no species of animals on the island that prey on the rabbits.
E) The virus that the government proposes to use has been successfully used elsewhere to control populations of rabbits.

Overgrazing by rabbits is harming agriculture.
Plan is to introduce a virus that will reduce rabbit population.
There is a small chance that the virus will infect bilby (native wildlife) too.

Conclusion: Plan may help agriculture but will clearly INCREASE threat to native wildlife.

Our conclusion says that the threat to native wildlife will increase because of the introduction of virus. So whatever is the threat to native wildlife right now, it will increase by the introduction of the virus. What is our assumption here?


A) There is less chance that the virus will infect domestic animals on Tambor than that it will infect wild animals of species native to the island.
Irrelevant. Comparison with domestic animals are out of scope. We are talking about wildlife only.

B) Overgrazing by rabbits does not pose the most significant current threat to the bilby.
Correct. We are concluding that threat will increase. What if overgrazing is a huge threat right now which could affect the bilby population badly? Then introducing the virus may actually reduce the threat - after all, there is a small chance that the virus will affect bilby. Introducing the virus will eliminate the overgrazing threat and introduce a small chance that the virus could affect bilby. So it is possible that introducing the virus may decrease the overall threat to wildlife.

C) There is at least one alternative means of reducing the rabbit population that would not involve any threat to the bilby.
Irrelevant. We are discussing the merits/demerits of this plan.

D) There are no species of animals on the island that prey on the rabbits.
If there are some species that prey on the rabbit, introducing the virus may reduce their food supply. So the wildlife may suffer. Hence our conclusion becomes stronger, if anything.

E) The virus that the government proposes to use has been successfully used elsewhere to control populations of rabbits.
We don't know and it doesn't matter. The virus has caused epidemic in rabbit population and that's all.

Answer (B)

I selected Answer A with the logic that domesticated animals fall into the category of "agriculture." Therefore, the risk to agriculture is low and has potential benefits while the risk to wildlife, which includes the Bilby that was discussed, is high. Would you mind explaining if there is something I am missing that makes this answer is incorrect?

Thank you!


Conclusion: government plan that Virus will not infect domestic animals (agriculture) but will infect wild animals.
In short, Government plan of virus is not a good solution.


A: Lets assume domestic animals === agriculture
Infect domestic animals < wild animals

The information is relative. How much effect? Whether it would be threat to survival? Or just minor effect. Still the virus solution can be implemented if the effect is minor even this minor this minor effect on wild animals more than domestic animals



B:
negate: Overgrazing by rabbits pose the most threat to bilby.

It means implementing virus solution doesn’t make much difference. Anyways bilby are under threat, so it doesn’t increase any threat to wild animals.
Secondly, overgrazing anyways disturbs agriculture
It means government plan of Virus solution is not bad. We can go ahead with this plan.

It destroy the conclusion, Hence information in B is important to draw the conclusion that government plan should not go ahead.


I hope it helps
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Understanding the argument -
Goal - reduce the rabbit population to save the island's agriculture ultimately.
Plan - introduce the virus.
Contrast introduced by "however" - a slight chance that the virus will infect the bilby, an endangered native herbivore.
Conclusion - The plan may be suitable for achieving the goal but detrimental to native wildlife.

Assumption - as of now, the wildlife has no issue with the rabbit population. What if the wildlife here, "a herbivore that feeds on plants," also gets affected by the rampant overgrazing by rabbits?

Option Elimination -

A) There is less chance that the virus will infect domestic animals on Tambor than that it will infect wild animals of species native to the island. - comparison with "domestic animals" out of scope.
B) Overgrazing by rabbits does not pose the most significant current threat to the bilby. - ok. If in doubt, negate it (as a last resort when you are left with two options at max. Applying negation to every option takes time, which we can't afford on the exam. If we need to apply the negation technique in every question, it means we may have missed the point. Spend time to understand the meaning)
C) There is at least one alternative means of reducing the rabbit population that would not involve any threat to the bilby. - alternate plan. Out of scope.
D) There are no species of animals on the island that prey on the rabbits. - how is it even related to the scope of the argument, "the plan is detrimental to wildlife"? Out of scope.
E) The virus that the government proposes to use has been successfully used elsewhere to control populations of rabbits. Good, but our scope is "the plan is detrimental to wildlife." Does it even talk about the scope? It just tries to mislead using some familiar words from the argument. Distortion.
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This is a high quality question and i agree with the solution.


B makes sense, simply by the negation tactic. for example. if the overgrazing by rabbits DOES pose the most significant current threat to the bilby, then, would it being a larger threat than the virus, call into question the conclusion that "The government's plan, therefore, may serve the interests of agriculture but will clearly increase the threat to native wildlife."?

The answer to this question, is of course, yes. If the rabbits themselves pose the most significant threat, then the eradication of the rabbits will actually decrease the threat to the biliby, relative to the threat of the virus.
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So, the argument assumes that the current threat to the bilby from the virus is significant enough to matter.

But if something else posed a far greater threat to the bilby (like overgrazing from rabbits), the additional virus risk might not be as concerning.

Therefore, the assumption that overgrazing is not the biggest threat to the bilby allows the argument to emphasize the potential danger of the virus, making B the correct answer.


Hope it helps :)
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Hi KarishmaB,

Love your explanations. Always on point!


In this question though, I have a doubt. How are we inferring a comparison between the threat levels of overgrazing and of a viral epidemic? Choice B says "most significant current threat", and the stimulus says "a small chance of viral infection". Now, can't the most significant current threat be lower in degree of threat than "a small chance of viral infection"? In your explanation, you have equated "most significant threat" to "a huge threat". Isn't "most" a relative term, which need not mean "huge"?
So, if I'm correct, how are we inferring that "most significant current threat" will "certainly" be greater than "a small chance of viral infection"? Are we using a contrast between "significant" and "small", and ignoring the governing impact of "most"?

Also, in your explanation, you've used the words "may" and "possible" in the conclusion. However, in the stimulus, the conclusion says "will definitely increase the threat". So, this doesn't seem to be a case of a "likely" conclusion either. Had it been one, then there wouldn't have been a need for this debate.

A valid necessary assumption, in my modest opinion, would be that the threat of overgrazing must not be greater than the threat of viral epidemic. We don't "need" overgrazing to not be the "most significant" threat or even "least significant". Even if it is "the most significant threat", it could still be lower in degree than the threat of a viral epidemic.

I hope I have been able to put my point across. I'm trying to identify whether I've missed some important clue.

Looking forward to the discussion.

Thanks and regards,


KarishmaB
s1lntz
Rabbits were introduced to Tambor Island in the nineteenth century. Overgrazing by the enormous rabbit population now menaces the island's agriculture. The government proposes to reduce the population by using a virus that has caused devastating epidemics in rabbit populations elsewhere. There is, however, a small chance that the virus will infect the bilby, an endangered native herbivore. The government's plan, therefore, may serve the interests of agriculture but will clearly increase the threat to native wildlife.

The argument above assumes which of the following?

A) There is less chance that the virus will infect domestic animals on Tambor than that it will infect wild animals of species native to the island.
B) Overgrazing by rabbits does not pose the most significant current threat to the bilby.
C) There is at least one alternative means of reducing the rabbit population that would not involve any threat to the bilby.
D) There are no species of animals on the island that prey on the rabbits.
E) The virus that the government proposes to use has been successfully used elsewhere to control populations of rabbits.

Overgrazing by rabbits is harming agriculture.
Plan is to introduce a virus that will reduce rabbit population.
There is a small chance that the virus will infect bilby (native wildlife) too.

Conclusion: Plan may help agriculture but will clearly INCREASE threat to native wildlife.

Our conclusion says that the threat to native wildlife will increase because of the introduction of virus. So whatever is the threat to native wildlife right now, it will increase by the introduction of the virus. What is our assumption here?


A) There is less chance that the virus will infect domestic animals on Tambor than that it will infect wild animals of species native to the island.
Irrelevant. Comparison with domestic animals are out of scope. We are talking about wildlife only.

B) Overgrazing by rabbits does not pose the most significant current threat to the bilby.
Correct. We are concluding that threat will increase. What if overgrazing is a huge threat right now which could affect the bilby population badly? Then introducing the virus may actually reduce the threat - after all, there is a small chance that the virus will affect bilby. Introducing the virus will eliminate the overgrazing threat and introduce a small chance that the virus could affect bilby. So it is possible that introducing the virus may decrease the overall threat to wildlife.

C) There is at least one alternative means of reducing the rabbit population that would not involve any threat to the bilby.
Irrelevant. We are discussing the merits/demerits of this plan.

D) There are no species of animals on the island that prey on the rabbits.
If there are some species that prey on the rabbit, introducing the virus may reduce their food supply. So the wildlife may suffer. Hence our conclusion becomes stronger, if anything.

E) The virus that the government proposes to use has been successfully used elsewhere to control populations of rabbits.
We don't know and it doesn't matter. The virus has caused epidemic in rabbit population and that's all.

Answer (B)
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Dragonoid
Hi KarishmaB,

Love your explanations. Always on point!


In this question though, I have a doubt. How are we inferring a comparison between the threat levels of overgrazing and of a viral epidemic? Choice B says "most significant current threat", and the stimulus says "a small chance of viral infection". Now, can't the most significant current threat be lower in degree of threat than "a small chance of viral infection"? In your explanation, you have equated "most significant threat" to "a huge threat". Isn't "most" a relative term, which need not mean "huge"?
So, if I'm correct, how are we inferring that "most significant current threat" will "certainly" be greater than "a small chance of viral infection"? Are we using a contrast between "significant" and "small", and ignoring the governing impact of "most"?

Also, in your explanation, you've used the words "may" and "possible" in the conclusion. However, in the stimulus, the conclusion says "will definitely increase the threat". So, this doesn't seem to be a case of a "likely" conclusion either. Had it been one, then there wouldn't have been a need for this debate.

A valid necessary assumption, in my modest opinion, would be that the threat of overgrazing must not be greater than the threat of viral epidemic. We don't "need" overgrazing to not be the "most significant" threat or even "least significant". Even if it is "the most significant threat", it could still be lower in degree than the threat of a viral epidemic.

I hope I have been able to put my point across. I'm trying to identify whether I've missed some important clue.

Looking forward to the discussion.

Thanks and regards,


KarishmaB
s1lntz
Rabbits were introduced to Tambor Island in the nineteenth century. Overgrazing by the enormous rabbit population now menaces the island's agriculture. The government proposes to reduce the population by using a virus that has caused devastating epidemics in rabbit populations elsewhere. There is, however, a small chance that the virus will infect the bilby, an endangered native herbivore. The government's plan, therefore, may serve the interests of agriculture but will clearly increase the threat to native wildlife.

The argument above assumes which of the following?

A) There is less chance that the virus will infect domestic animals on Tambor than that it will infect wild animals of species native to the island.
B) Overgrazing by rabbits does not pose the most significant current threat to the bilby.
C) There is at least one alternative means of reducing the rabbit population that would not involve any threat to the bilby.
D) There are no species of animals on the island that prey on the rabbits.
E) The virus that the government proposes to use has been successfully used elsewhere to control populations of rabbits.

Overgrazing by rabbits is harming agriculture.
Plan is to introduce a virus that will reduce rabbit population.
There is a small chance that the virus will infect bilby (native wildlife) too.

Conclusion: Plan may help agriculture but will clearly INCREASE threat to native wildlife.

Our conclusion says that the threat to native wildlife will increase because of the introduction of virus. So whatever is the threat to native wildlife right now, it will increase by the introduction of the virus. What is our assumption here?


A) There is less chance that the virus will infect domestic animals on Tambor than that it will infect wild animals of species native to the island.
Irrelevant. Comparison with domestic animals are out of scope. We are talking about wildlife only.

B) Overgrazing by rabbits does not pose the most significant current threat to the bilby.
Correct. We are concluding that threat will increase. What if overgrazing is a huge threat right now which could affect the bilby population badly? Then introducing the virus may actually reduce the threat - after all, there is a small chance that the virus will affect bilby. Introducing the virus will eliminate the overgrazing threat and introduce a small chance that the virus could affect bilby. So it is possible that introducing the virus may decrease the overall threat to wildlife.

C) There is at least one alternative means of reducing the rabbit population that would not involve any threat to the bilby.
Irrelevant. We are discussing the merits/demerits of this plan.

D) There are no species of animals on the island that prey on the rabbits.
If there are some species that prey on the rabbit, introducing the virus may reduce their food supply. So the wildlife may suffer. Hence our conclusion becomes stronger, if anything.

E) The virus that the government proposes to use has been successfully used elsewhere to control populations of rabbits.
We don't know and it doesn't matter. The virus has caused epidemic in rabbit population and that's all.

Answer (B)


The conclusion is a definite: The government's plan will clearly increase the threat to native wildlife.

The support given for this is that the plan introduces a small risk of virus infection reaching bilby.

Here is a question: What are the current significant threats to bilby? Is the rabbit population one of them? If yes, then the plan MAY NOT increase the threat. And there I have broken the author's conclusion. If the author says "A will definitely happen," even if I say that "A may not happen," his conclusion falls apart.

What must be true for his conclusion to hold?
Rabbits should not be significant threat to bilby in the current situation. If they are then their reduction (the plan) could actually help bilby overall.

Option (B) says that rabbits should not be the most significant current threat to bilby.

Of course that should be true. Rabbits should not be a significant current threat at all. Then automatically they should not be the most significant current threat.


Take a simpler situation:

What is necessary to conduct a successful performance tomorrow?
This is necessary - It should not rain tomorrow.
Then this is automatically necessary too - Tomorrow should not be the heaviest rainfall day of the year.
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