From the question stem it looks like an inference question

(A) Some part of the panthers’ current habitat is only of marginal quality.
Irrelevant and not mentioned anywhere in the passage.

(B) If the population of Florida panthers ever exceeds 250, it will be self-sustaining.
It is directly mentioned in the passage.

(C) Unless Florida panthers acquire a larger habitat, their population will not be self-sustaining.
Can be inferred from the passage. Till the time population doesn't reach 250 its not self sustaining and in current habitat the population cant grow hence in current habitat population cannot be self-sustaining. Correct.

(D) The population of Florida panthers will never increase much beyond its current level.
if the size of the habitat increases then the population can increase. Incorrect.

(E) Today, Florida panthers occupy a larger habitat than they did in the 1970s.
Cant be concluded from the passage. Maybe the habitat was bigger and Panthers were dying due to another reason like hunting.

Hence C is the correct answer.

Can someone explain why B is incorrect?

Posted from my mobile device

"The population must reach at least 250" is one condition which should be true in order to make the population self-sufficient.

In an option B

there is an assertion: if this condition is true, the population will be self-sufficient......Hence, B is incorrect because there could be other factors may affect to make the population self-sufficient.

Thanks = Kudos

Firstly, It is only between B and C.
I picked B over C so I want someone to give a better reasoning for C.

Or B can only be eliminated on the basis that it is already mentioned in the passage?

Thank you!
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Hi everyone,

So between B and C.

We know that ONE OF THE CONDITIONS for the panthers' population to be self sustaining is the number, 250. We also know that the current habitat does not support more than 100 panthers.

In order to eliminate B let's consider the following scenario: Enough panthers are introduced in the current habitat so that the minimum 250 is met. The problem now is that the current habitat won't support the extra ones and probably all the tigers but 100 of them will die.

Hence Option B is not a must be true statement.

with LSAT questions you need to careful with the wordings. The answer choices can be wrong with just one similar word.

Option B says- If the population of Florida panthers ever exceeds 250, it will be self-sustaining.

and the statement says their population must reach at least 250

population reaching at least 250 and population exceeding 250, say 251,255 or 260. We do not know. This is must be true question and the word 'exceeds' changes the meaning by a bit.

I know it's tricky, but after all lsat CRs needs to dealt with utmost concentration of wordings.

Dear rockz
As alluded Rupesh1Nonly
"The population must reach at least 250" is one condition


Maybe my few cents will helps other to clearly assimilate "conditional reasoning" [marker : If .. THEN].
Stimulus states:
....population must reach at least 250 if it is to be self-sustaining.

It it is to be self-sustaining - "Sufficient condition"
population must reach at least 250 - "Necessary condition"

There ONLY two plausibly scenarios:
Direct statement: [A -- > B]

If it is to be self-sustaining --- > population must reach at least 250

Contrapositive [Not B --- > Not A]

population Will NOT reach at least 250 ---> it WILL NOT be self-sustaining

Answer B affirms:

(B) If the population of Florida panthers ever exceeds 250, it will be self-sustaining.

Such RE-interpretation called "mistake reversal"
Take into consideration that there may be more then ONE "Necessary condition"

Thus, If the population of Florida panthers ever exceeds 250 this activity does not necessarily lead to self-sustaining. That is mere one of many "Necessary conditions"

In addition to that, I believe the option B says 'ever exceeds' - which is intending that even if the population exceeds once and then drops back - it will still be self-sustaining

(C) Unless Florida panthers acquire a larger habitat, their population will not be self-sustaining.

I discarded option C because of the word "acquire". Florida Panthers is a species and they cant acquire land. is my reasoning wrong ? can anyone explain it ?

NinjaNightCapt
You are looking into the passage too hard so much so that you are focusing on irrelevant things. What you are doing is a common mistake that test takers do in their initial stage of prep. I can't deny it that i don't make this type of mistake now because i still do sometimes(took almost two and a half minutes to solve).

Acquire doesn't literally mean that panthers are going to acquire land.

There are 70 to 100 Florida panthers alive today. - A fact.
This represents a very large increase over their numbers in the 1970s, - A fact again.
but their population must reach at least 250 if it is to be self-sustaining. - Conclusion. Even though there is a large increase, the population is not sustainable.
Their current habitat is not large enough to support any more of these animals, however. - Reason for reaching out that conclusion.

If the statements above are true, which one of the following must also be true?

(A) Some part of the panthers’ current habitat is only of marginal quality. - Irrelavant.

(B) If the population of Florida panthers ever exceeds 250, it will be self-sustaining. - A better explanation already exists in above explanation(A ----> B and reversal mistake is Not B ----> Not A). You need to master that principle to solve the questions with that ease, it saves a lot of time. For this option I thought why this option is reiterating what is already mentioned in the passage. Also, more importantly, why 'ever' is present in the option. So, finally what I interpreted 'ever' as is that does it mean that reaching 251 first time the population becomes self sustaining? No..!! As far as population is concerned it is not a one way game. Some animals would die and some would be born to make a net effect called population. The way this option presents information it is like whenever it crosses 250 population becomes self sustaining, which is not the case.

(C) Unless Florida panthers acquire a larger habitat, their population will not be self-sustaining. - This is the only one left. Additionally, it directly addresses the conclusion.

(D) The population of Florida panthers will never increase much beyond its current level. - Future can be anything but 'never' ruins the option.

(E) Today, Florida panthers occupy a larger habitat than they did in the 1970s. - This is a nice trap. Yes, it may be true but is it necessary that that must have been the case. For example(against case) - in 1970s the land for habitat was 10 acres with a population of 10. Now the habitat is still 10 acres but population is between 70 to 100 which is kind of peak that these animals can reach(e.g. density-wise) in that habitat. Thus, the option falls apart.

HTH.
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STIMULUS
Argument; not fact set

Premise 1: There are 70 to 100 Florida panthers alive today.

Premise 2: This represents a very large increase over their numbers in the 1970s

Counter-premise 1: Their current habitat is not large enough to support any more of these animals, however.

Conclusion 1: but their population must reach at least 250 if it is to be self-sustaining.


QUESTION STEM
Must Be True

So, flow of information must be only from Stimulus to Question stem, i.e., assume everything said by the author to be true but do not assume anything additional that does not fall under the umbrella of ideas mentioned in the stimulus.


ANSWER CHOICES
(A): "Quality" has not been mentioned anywhere in the stimulus. This is therefore, out of scope.

(B): Stimulus mentioned "...at least 250" for the panther population to become self-sustaining. This option on the other hand, states a certainty that if it "...ever exceeds 250, it will be self-sustaining". Author used the word "at least" to indicate that the number could be more based on other, unstated factors. However, the answer choice uses the word "will" - if this number "ever exceeds" 250. Never ignore the word play!

(C): Correct option - First, this is an answer choice that does not being in new information. Second, this answer choice could easily be created by combining ideas given in the Premise 1, Conclusion 1 and Counter-premise 1. Their current population is between 70 and 100 - for population to be self-sustaining it has to be "at least" 250 (could be more based on unstated factors) - current habitat is not large enough to support "any more" of these animals.

(D): "...will never increase" is a strong word play which had not been used in the stimulus for the presented idea. Stimulus only concludes that for the panther population to be self-sustaining, it must at least be 250, and the current habitat cannot allow any more of these animals.

(E): Could be true or could not be true. Answer choice however "Must Be True".

Stimulus mentioned "...at least 250" for the panther population to become self-sustaining. This option on the other hand, states a certainty that if it "...ever exceeds 250, it will be self-sustaining". Author used the word "at least" to indicate that the number could be more based on other, unstated factors. However, the answer choice uses the word "will" - if this number "ever exceeds" 250. Never ignore the word play!

Please refer to my answer if you would like to read my reasoning on the other options as well.