Target Test Prep GMAT Verbal Challenge Question 5

Solution:

There are in the sentence two areas in which issues appear.

First, the comparison between the fish farms' harming and the fish farms' helping has both to be logical and to work with the rest of the sentence.

Then the list of ways in which the farms are harmful has to be parallel and make sense.

(A) While industry insiders insist that fish farming reduces pressure on wild fish stocks, outside experts have suggested that actually the farms do more harm than help, by catalyzing the spread of diseases, of parasites such as sea lice, and causing astronomical increases in the levels of pollution in wild ecosystems.

“Do more harm than help” does not work, since while “farms do harm” makes sense, “farms do … help” does not make sense in this context.

Also, the list of ways in which the farms are harmful is not logical. The repetition of “of” in the beginnings of the first two items in the list signals that what introduces the list is “by catalyzing the spread,” but the third item in the list does not work logically with “by catalyzing the spread” as we can see by considering the following:

by catalyzing the spread of diseases – makes sense

by catalyzing the spread of parasites such as sea lice – makes sense

by catalyzing the spread causing astronomical increases in the levels of pollution in wild ecosystems – does not make sense

(B) While industry insiders insist that fish farming reduces pressure on wild fish stocks, outside experts have suggested that actually the farms do more harm than they help, by catalyzing the spread of diseases, the spread of parasites such as sea lice, and causing astronomical increases in the levels of pollution in wild ecosystems.

In this version “do more harm than they help” nonsensically conveys that the farms do more harm than the harm they help.

Also, the list of ways in which the farms are harmful is not logical. What seems to introduce the list is “by catalyzing,” but the third item in the list does not work logically with “by catalyzing,” as we can see by combining the two:

by catalyzing causing astronomical increases

CORRECT ANSWER(C) While industry insiders insist that fish farming reduces pressure on wild fish stocks, outside experts have suggested that actually the farms harm more than they help, by catalyzing the spread of diseases and that of parasites such as sea lice and causing astronomical increases in the levels of pollution in wild ecosystems.

“Harm more than they help” effectively expresses the comparison between the fish farms' harming and the fish farms' helping.

Also, this version effectively expresses the ways in which the fish farms are harmful by using an outer list and a nested list.

The outer list is:

by:

catalyzing …

causing …

The nested list is:

catalyzing:

the spread of diseases

that of parasites such as sea lice

Notice, the use of “that,” which refers to “the spread,” in the second item in this nested list may make this choice seem to be incorrect. To correctly answer sentence correction questions, we have to carefully evaluate logic and avoid being thrown off by structures that “sound wrong” at first.

(D) While industry insiders insist that fish farming reduces pressure on wild fish stocks, outside experts have suggested that actually the farms are more harmful than helpful, catalyze both the spread of diseases and parasites such as sea lice, and causing astronomical increases in the levels of pollution in wild ecosystems.

In this version, the comparison between the fish farms' harming and the fish farms' helping, “more harmful than helpful,” is effective.

However, the list that appears in this version does not work logically with what introduces the list, “the farms,” as we can see by considering the following:

the farms (are more harmful than helpful, catalyze both the spread of diseases and parasites such as sea lice, and causing astronomical increases in)

the farms are more harmful than helpful, the farms catalyze both the spread of diseases and parasites such as sea lice, and the farms causing astronomical increases in

We can see that “the farms causing astronomical increases” does not make sense in this context.

Also, the nested list “catalyze both the spread of diseases and parasites such as sea lice” does not make sense, since “catalyze … sea lice” does not make sense.

(E) While industry insiders insist that fish farming reduces pressure on wild fish stocks, outside experts have suggested that actually the farms are harming more than helping, catalyze both the spread of diseases, parasites such as sea lice, and causing to astronomically increase the levels of pollution in wild ecosystems.

The list that makes up the choice does not work logically with what introduces the list, “the farms,” as we can see by considering the following:

the farms (are harming more than helping, catalyze both the spread of diseases, parasites such as sea lice, and causing to astronomically increase)

the farms are harming more than helping, the farms catalyze both the spread of diseases, parasites such as sea lice, and the farms causing to astronomically increase

We can see that “the farms causing to astronomically increase” does not make sense in this context.

Also, “both” is meant to introduce a two item list, but, in this case, there is no “and” between the two items that “both” seems to introduce, “the spread of diseases” and “parasites such as sea lice.” So, the list introduced by “both” is not logically constructed, and what items are meant to be in the list is not entirely clear.

Also, the items in the list introduced by “both” do not work logically with what introduces the list, “catalyze,” as we can see by considering the following:

catalyze … the spread of diseases – makes sense

catalyze … parasites such as sea lice – does not make sense