GetThisDone wrote:
For nearly a century, physiologists erroneously believed that
a buildup of lactic acid in muscle tissue was responsible for the soreness that many people experience after strenuous exercise. The acid, they claimed, is the waste produced by metabolic activity in the muscle and reaches “threshold” levels, causing soreness, when the muscle has depleted its oxygen supply.
Researchers have recently discovered, however, that lactic acid is actually the fuel that powers muscular activity. Therefore, the cause of muscle soreness remains unknown. In the argument above, the portions in boldface play which of the following roles?
A) The first is an assertion that the author accepts as true; the second is a consideration in support of that assertion.
B) The first is an assertion that the author accepts as true; the second describes a situation that the author posits as contrary to that assertion.
C) The first is an assertion that the author argues against; the second is evidence presented as contrary to the author’s argument.
D) The first is evidence that the author believes is no longer valid; the second is additional evidence that the author uses to support his main point.
E) The first is a claim that the author believes to be invalid; the second is the author’s main point.
Main CR Qs link -
https://gmatclub.com/forum/cr-qs-600-700 ... 31508.htmlOFFICIAL EXPLANATION
The question asks us to analyze the structure of the argument. Specifically, it asks us to determine the relationship of the two bolded sentences to the argument as a whole. To do this effectively, we need first to determine the conclusion of the argument. In this case, the conclusion is the final sentence, which follows from the evidence presented in the rest of the argument. So we know that the correct answer cannot describe either bolded portion as the author's final conclusion.
The first bolded portion is presented as an earlier, erroneous belief. In evaluating the answer choices, we should look to eliminate any that suggest the author agrees with this first statement. The second bolded statement shows that the earlier theory (that lactic acid causes soreness) was incorrect, and thus also provides evidence in support of the author's conclusion. So we know that the correct answer must describe the second bolded portion as supporting the conclusion. The correct answer must describe both portions correctly, not just one or the other.
(A) This choice misrepresents the first bolded portion by claiming that the author accepts it as true, when the author actually presents it as an incorrect, outdated belief. The second portion is also incorrect because it indicates that the second bolded portion supports the first one.
(B) This choice also misrepresents the first portion, for the reason described above. It corrects the second bolded portion, however, by describing it as contradictory to the first portion.
(C) The first portion is correctly described as an assertion that the author does not believe to be true. Yet the second portion is incorrectly described as going against the author's final conclusion.
(D) CORRECT. This choice correctly represents the first portion by saying the author believes it is no longer valid. The second portion is correctly described as evidence in support of the author's conclusion.
(E) The first portion is correctly described as evidence considered by the author to be invalid. However, this choice misrepresents the second portion as the conclusion, when it is actually evidence given in support of the conclusion.
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