The information in the passage most helps to answer which one of the following questions?

Manvir on June 27 at 09:37PM

Why is E correct?

How do we know that chlorine is the MOST damaging constituent element of CFCs since the passage doesn't mention/compare the others? Couldn't an unmentioned constituent element be even more damaging?

2 Replies

Albert on June 29 at 03:19PM

Same question, though other options don't seem to fit either.

Victoria on July 7 at 08:15PM

Hi @manvir and @alberttang,

Happy to help!

The correct answer for this question is best determined through a process of elimination. You are correct that it is possible that another constituent element of CFCs could be more damaging to ozone, but it doesn't really make sense that the passage would outline the impacts that chlorine has on the ozone while omitting the impacts that a more damaging element of CFCs has on the ozone.

The other answer choices are even less supported than answer choice (E) which is why it is correct.

Answer choice (A) is incorrect because we simply learn that Molina and Rowland "showed" the impacts of CFCs on the ozone and "stud[ied]" two types of CFCs (lines 14 to 24). We are not provided with any further information on what laboratory experiments were or were not conducted by the pair in their research.

Answer choice (B) is incorrect because the passage does not mention this. We know that the atmosphere contained the accumulation of five years of CFC production in 1974 (lines 34 to 36) and we know that the Montreal Protocol banned the production of CFCs in 1987 (lines 54 to 56), but we do not know the estimated concentration of CFCs in the atmosphere in 1987.

Answer choice (C) is incorrect for the same reason as answer choice (B). We know that Molina testified before Congress at some time between the early 1970s and 1987, but we do not know the exact year.

Answer choice (D) is incorrect for a similar reason as the one you've alluded to above. We know that chlorine destroys the ozone, but we do not know if any other elements also destroy ozone or are even more destructive than chlorine. Therefore, we cannot conclude based on the information in the passage whether chemicals which do not contain chlorine will also contribute to the destruction of ozone.

As a result, answer choice (E) is our strongest answer choice as we know for sure that chlorine is an element of CFCs which destroys ozone and we know that it was the element which was focused on by Molina and Rowland in their work.

Hope this is helpful! Please let us know if you have any further questions.