Self-study
Sinking large, obsolete pieces of equipment in coral areas is said to provide much-needed habitats for marine life. █████ ██████████ ████ █████ ████ ███ ████████ ██ ████████████ ██████ ████████ ██ ███ ██ ████ ████ ████████ ██ ████████████ ███████ ████ ██ ██ ████ ███████ ███████████ █████████ ███ ███ ████████ ███ █████ ██ ██████ ██████████ ███████ ██ ███████ █████
Stimulus Summary
As with many Argument Part questions, the stimulus starts with other people's argument. Some people think sinking big, obsolete pieces of equipment in coral areas provides habitats for marine life, and that therefore the practice of sinking these kinds of equipment in coral areas is ecologically sound.
(We know the first two sentences describe other people's argument, because of the phrases "is said" and "proponents say.")
The author's argument begins in the third sentence. She concludes that this practice—referring to the sinking of big, obsolete pieces of equipment in coral areas—is ecologically unsound even if it provides the habitats that other people say it does. We know that's the author's conclusion, because the next part of the sentence uses "for" as a support indicator. This signals that the claim "the practice might upset an area's ecological balance in unknown ways" is designed to provide support to the claim that the practice is ecologically unsound.
(By the way, note that the phrase "even if" does not introduce a conditional statement. "Even if" just means that the other part of the sentence is still true, regardless of whether the part after "even if" is true.)
Anticipation
The question stem asks us for the role of the claim that happens to follow the "for" in the second half of the last sentence. As explained in the Stimulus Summary above, that claim provides support to the author's conclusion. We know it provides support because it follows the word "for," which, in this context, means the same thing as "because" or "since."
Also, although this isn't required to identify the role of the claim, it may help to think about cost/benefit method of reasoning. The proponents of the practice point out what they view to be a benefit of sinking the equipment in coral areas. Because of this alleged benefit, they think the practice is ecologically safe. The author pushes back and points out a risk of that practice. The author assumes this risk outweighs the alleged benefit cited by the proponents. That's why the author believes the practice isn't ecologically safe. The claim we're asked about is the claim that points out a risk of the practice.
8.
Which one of the following ████ ██████████ █████████ ███ ████ ██████ ██ ███ ████████ ██ ███ █████ ████ ███ ████████ ██ ███████ ██████ ████████ ██████ ██ █████████ ██ █████ █████ ███ █████ ██ ██████ ██████████ ███████ ██ ███████ █████
a
It is intended ██ ██ █ ███████ ██ ███ █████████
The claim we're asked about provides support to the author's conclusion. Because it plays a role in the logic of the author's argument, it's not merely a summary of the author's argument. A summary would recap the premise and conclusion.
b
It is a █████ ████ ███ ████████ ████████ ██ ███████
The claim the author tries to refute is the proponent's view that the practice is ecologically sound. But the claim we're asked about is something the author believes is true. In fact, she's using it to support her own conclusion.
c
It is a █████ ████ ███ ████████ ████████ ██ ████████████ ██ ████ ████ ████ ████ █████ ██ ██ █████
(C) describes the first sentence. The author contends that even if the practice provides habitats for marine life, that's not enough to show the practice is ecologically sound. But the claim we're asked about isn't the first sentence.
d
It is the ████ ██████████ ██ ███ █████████
The main conclusion is that the practice is ecologically unsound, even if it provides much-needed habitats. The claim we're asked about provides support to the conclusion.
e
It is a ███████ ██ ███ █████████
This accurately describes the role of the claim we're asked about. See the explanation under Stimulus Summary for a full breakdown. We know the claim that the practice may upset an area's ecological balance supports the conclusion, because of the word "for," which is used just like "since" or "because" in this context. Also, we know the claim is a premise (rather than an intermediate conclusion), because there's no other line that is intended to support the claim.