Trout populations are rising in United States rivers, which

Question

Trout populations are rising in United States rivers, which suggests it is time to shift conservation efforts from keeping raw numbers high to having the right kind of trout in the right area. For years, nonnative trout species were used to stock rivers for fishing, and these new arrivals crowded out indigenous species. Conservation should thus focus on restoring habitats, since habitat restoration will enable indigenous trout populations to rebound, and since _________.

Which of the following, if true, would most logically complete the argument?

A) the degradation of trout habitats caused the initial trout population declines
B) the nonnative trout population can be kept under control if it is fished above current levels
C) the right kind of trout are increasing in some areas with habitat degradation
D) restoring habitats focuses conservation efforts
E) the overabundance of indigenous trout caused the initial degradation of trout habitats

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Official Answer

A

MartyMurray · Accepted Answer

I think GMAC has to restore quality control in Critical Reasoning.

In the past, official Sentence Correction questions were occasionally debatable, but official Critical Reasoning questions were reliably high quality. Now, there are multiple flawed Critical Reasoning questions on the official practice tests.

I'm likely going to reach out to GMAC about this issue. It will probably help if others do as well.

At the same time, it's also helpful to see whether this question is gettable, and the truth is that we can eliminate our way to the correct answer.

Let's work our way from (E) to (A), eliminating each incorrect choice to arrive at the credited, though not optimally constructed, answer.

E) the overabundance of indigenous trout caused the initial degradation of trout habitats

The fact that the trout caused the degradation of their own habitats is not a reason to focus on restoring habitats.

Eliminate.

D) restoring habitats focuses conservation efforts

This could be a reason to focus on restoring habitats, but it's not a very strong one. So, probably, it is not correct.

Also, it doesn't have anything to do with the key idea in the passage that "it is time to shift conservation efforts from keeping raw numbers high to having the right kind of trout in the right area."

Eliminate.

C) the right kind of trout are increasing in some areas with habitat degradation

The fact that "the right kind of trout" are increasing in number in areas where the habitats have not been restored is certainly not a reason to restore habitats.

Eliminate.

B) the nonnative trout population can be kept under control if it is fished above current levels

The key to eliminating this choice is that it mentions fishing "above the current levels." In other words, it indicates that an increase in fishing of nonnative trout is necessary for keeping their population under control.

The fact that an increase in fishing would work is not a reason to restore habitats.

Eliminate.

A) the degradation of trout habitats caused the initial trout population declines

While this choice does not work perfectly, it's the best of the bunch.

Why? Because, if the degradation caused the initial declines, then restoration may have the opposite effect, helping the native trout to thrive.

That said, I think that what may really be the case is that the last sentence of the passage is miswritten and has an extra word, the word "and."

Let's see what happens if we edit the last sentence, removing "and."

habitat restoration will enable indigenous trout populations to rebound,  and  since _________.

If we add choice (A) we get the following:

habitat restoration will enable indigenous trout populations to rebound, since  the degradation of trout habitats caused the initial trout population declines

That version makes complete sense. After all, if the decline in indigenous populations occurred because of habitat degradation, then restoring habitat should reverse the process.

In any case, a key takeaway is that, even if a question isn't perfectly constructed, there's a good chance we can eliminate our way to the correct answer and put some points on the board.

KarishmaB · Answer

These days I am finding myself disagreeing with more and more official questions!

Don't know if it is the Focus effect for which I need to re-calibrate, but I wouldn't have thought it to be an official question. I would consider option (A) to be a trap. Uses the same words, seems to fit into the context, but isn't very logical. If I break down the last sentence, I get: Premise: since habitat restoration will enable indigenous trout populations to rebound and since .... (looking for another premise) Conclusion: Conservation should thus focus on restoring habitats, First premise makes sense. Restore habitat since it will enable indigenous trout populations to rebound ('right kind of fish' focus). Restore habitat since ... (A): the degradation of trout habitats caused the initial trout population declines I am thinking why does this have anything to do with what we have to do now, for future, for right kind of fish focus. 'Why the decline happened in the past' is irrelevant when we are already given that restoring habitat will enable indigenous to rebound in the previous premise. When we are using comma + and + since, I am looking for another premise. Hence, I don't really have an explanation here. GMAT-Club-Forum-ck4pp2sn.png

sayan640 · Answer

KarishmaB  I found B more lucrative than A , given than the right kind of fishes need to be kept . Any thought ?  MartyMurray

Posted from my mobile device

KarishmaB · Answer

What is the source of this question? No option makes sense to me.

sayan640 · Answer

Looks like the source is Gmat prep focus mock. It was posted by my friend  ashutosh_73

Bunuel · Answer

Can anyone of you provide with the screenshot of the question? Thank you!

ashutosh_73 · Answer

sayan640 KarishmaB Bunuel Question is from Prep test no. 4 https://gmatclub.com/forum/download/file.php?id=81922 GMAT-Club-Forum-7axi99m8.png

ashutosh_73 · Answer

Hi KarishmaB Can we say the same for the below another question question from PT 4? It was really frustrating during the Mock. Confidence takes a hit!! GMAT-Club-Forum-5dksi3ep.png

8Harshitsharma · Answer

This is a strengthener fill-in-the-blank question. We need to give reason for supporting the conclusion.

Option E makes sense to me, it gives a reason why habitat restoration should be a focus.

The argument states that restoring habitats will "REBOUND" (start INCREASING) the indigenous fish population. So choice A is incorrect as it talks about decline. If there were no decline in habitat then it's possible that the fish population would've stayed the same and would not INCREASE. So this choice doesn't even support the rebound part of the argument.

Opt E states: that since the target trout fishes are indigenous, the habitat must have SUPPORTED their population INCREASE until their overabundance caused their habitat to degrade, leading to a decrease in their population. => So if we restore the habitat again we can have the same conditions that increased the population in the past. Not a great option but convincing enough.

Opt B states: It is wrong because it assumes "if fished above current levels" - we don't know whether this condition will be met or not. Eliminate B.

einstein801 · Answer

A.

Focus is ensuring diversity/right kind of trout.

What  completes the statement best? Answer must address the diversity of trout --> A.

vishwathols · Answer

I believe the option A is correct based on the following rationale please correct me if I am wrong Indigenous trout populations will rebound because of habitat restoration. This would be true if the initial trout population was affected by habitat degradation. The trouts would have failed to thrive in a degrading environment and hence population declined Then in order to increase trout population people would have added non-native trout population into the river. For some reason, the trouts population is now restored but with non native trouts dominating the native trouts in number I would have easily picked option A if it had specifically mentioned indigenous trout population rather than initial trout population Another strong contender among the options would be E IMO, if not for the paradoxical element in it GMAT-Club-Forum-z8xl8wb9.png

Arjun123321 · Answer

This is a little hard question and even I went for choosing B over A, as it explained how the other probllem of Non-Native Trout Population will be handled. But my thinking here is wrong since we need a option which will most logically complete the last sentence, which inherently tries to explain how to solve the problem of DECLINING INDIGENOUS TROUT POPULATION mentioned in the passage. We need an option which most logically helps us understand why we should focus on "Restoring Habitats" (AS MENTIONED IN THE LAST SENTENCE) and option A explains that. The following is my thinking: 1. Non-native trout species increased, which lead to native trout population decrease. 2. The last line indicates that there is a need for restoration of habitats, thus implying that something has happened to destroy the earlier existing habitat. The ONLY change which is mentioned in the passage that might have led to destruction of habitat is the infestation of the Non-Native Trouts. 3.We can infer from the above, that the reason for decline in NATIVE TROUT was due to change in habitat, which has occured due to excessive Non-Native Trouts. The option which most logically explains the above is A) which states that the initial degradation OF THE NATIVE TROUT AFTER INFESTATION OF THE NON NATIVE TROUTS, AND NOT THE ONE IMPLIED IN SENTENCE 1 ] was caused due to degradation of the earlier habitats. GMAT-Club-Forum-8c9ke04t.png

sayan640 · Answer

MartyMurray  any thoughts?

Posted from my mobile device

sayan640 · Answer

we dont see any question here ashutosh_73 Posted from my mobile device GMAT-Club-Forum-wfkwtycc.png

MickV · Answer

While I did not go for answer A initially, upon checking the question more carefully I think the following is the underlying logic of A being the right answer. Since trout populations have been rising and raw numbers have been high, it becomes time to develop a focused effort on having the right kind of trout in the right area. The solution that we are looking for should therefore, ideally, enable both the raw trout numbers to remain high, while also indigenous trout populations can rebound. Answer A actually mentions that not restoring trout habitats (thus letting them degrade over time) caused initial declines in the trout population. Therefore, answer A basically finishes the argument by (indirectly) concluding that restoring habitats will enable both the raw numbers to remain high while also getting the right kind of trout in the right area. ashutosh_73 GMAT-Club-Forum-rozs7j96.png

Dbrunik · Answer

did you ever get a response from GMAC? I didnt find this question all that complicated. A makes sense. the others are obviously wrong.

Elite097 · Answer

A) The degradation of trout habitats caused the initial trout population declines
This strengthens the argument by showing that habitat degradation is the root cause of the indigenous trout population's decline. If habitat degradation caused the problem, restoring habitats is a logical and effective solution.
Correct answer because it directly supports the proposed focus on habitat restoration.
B) The nonnative trout population can be kept under control if it is fished above current levels
This suggests a strategy to control nonnative trout but does not connect to the argument's focus on habitat restoration as the key to enabling indigenous trout populations to rebound.
Incorrect because it shifts the focus to controlling nonnative trout instead of restoring habitats.
C) The right kind of trout are increasing in some areas with habitat degradation
This contradicts the argument by implying that habitat degradation does not prevent indigenous trout populations from rebounding. If true, it weakens the argument for habitat restoration.
Incorrect because it undermines the argument.
D) Restoring habitats focuses conservation efforts
This is too vague and does not provide a logical reason why habitat restoration is the key to enabling indigenous trout populations to rebound. It lacks specific support for the conclusion.
Incorrect because it is uninformative and does not add meaningful evidence.
E) The overabundance of indigenous trout caused the initial degradation of trout habitats
This weakens the argument by suggesting that indigenous trout were responsible for habitat degradation. If true, habitat restoration might not lead to their rebound.
Incorrect because it undermines the argument.

Pipi0914 · Answer

I just encountered this question... it is from GMAT official prep exam 4

Trout populations are rising in United States rivers, which

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Trout populations are rising in United States rivers, which