What does the Question Stem tell us?
ID the Conclusion. Keep your eye out for intermediary conclusions, and be wary of the last sentence. The main point tends to appear before that.
Break down the Stimulus:
The argument opens with a rather confusing criticism of a criticism, stating that the article to which it is responding made an unjust critique of environmental groups. The next line paraphrases the article, and, after the turnaround word "but," the final line gives evidence in support of the criticized environmental group's claim. In supporting the environmental group, the last line also gives evidence supporting the first line which called the article's critique unjust. That makes this first line of text the main conclusion.
Any prephrase?
The main point is not just about the study or the environmental group; it's about the article to which it is responding. That has to be part of the correct answer as well.
Correct answer:
E
Answer choice analysis:
A) This is the premise.
B) Tempting, but while our letter-writer criticizes the criticism of this claim, that's not the same thing as endorsing the claim. While s/he implicitly endorses the claim, the explicit point is that the article was flawed.
C) There are no prescriptive ("should") statements in this stimulus, so we cannot have a prescriptive statement describe the argument's main point.
D) Also tempting, because it seems like something one might conclude from this information. But in fact, the study is just of the population, not the means that sustain the population, so even if the population is artificially sustained, the study could still be done properly. It is the use of the study by the article that our author takes issue with, not the study itself.
E) Correct! The only answer that explicitly addresses the article to which the letter responds.
Takeaway/Pattern: If an ID the Conclusion question addresses a specific entity, that entity must feature in the correct answer choice.
#officialexplanation