GPrep - There are no legal limits, as there are for cod and

Sentences that are fully underlined can be intimidating — we aren't sure of anything in the sentence. However, this is often a blessing in disguise. Since there may be multiple errors in the sentence, there may be multiple opportunities for us to rule out answer options.

Scanning over our sentence, we notice that the sentence sets up a comparison between the existence of legal size limits for cod and haddock and the lack of legal size limits for monkfish. Comparison questions are a favorite on the GMAT since they test a couple things — parallelism and "like/unlike" vs. "as". Like with a list or a series, things being compared must have parallel structure. This concept is pretty easy to test for on a question-by-question basis, but "like" vs. "as" is another one of the GMAT Sentence Correction rules on idiom and diction we need to have memorized: "like" is used to compare two objects (nouns), while "as" is used to compare two actions (verbs).

Looking at A we see our comparison is between

• There are no legal limits … on the size of monkfish that can be caught

and

• there are [legal limits] for cod and haddock

... which actually works fine — the two things being compared are parallel and are both verbs, which fits with the use of "as". We can keep A and check our other answers.

B sets up a comparison using "unlike", so we know we should be comparing two nouns. However, the first part of our sentence doesn't change at all, giving us a comparison between

• There are no legal limits … on the size of monkfish that can be caught

and

• cod and haddock

So we have a parallelism issue, (comparing a lack of legal limits to a fish doesn't make much sense), AND we have an issue with idiom and diction ("unlike" can't compare a verb to a noun). We can eliminate B based on either.

Looking at D and E, our other "unlike" answer choices, we see similar issues. In D, we compare "there are no legal size limits on catching monkfish" with "cod and haddock". In E, we compare "there are no legal size limits on catching monkfish" with "catching cod and haddock (where "catching" is a gerund, a type of noun). We can eliminate both.

This leaves us with A and C. C doesn't use "like" or "as", so we're out of luck there. It does, however, use the word "which", which (... get it) should ring some more idiom and diction bells. On the GMAT, the word "which" must refer to the closest noun. For example:

• We ran to the store, which made us tired.

is something we might say colloquially — the act of running made us tired. However, on the GMAT, this sentence would indicate that the store itself made us tired.

Looking at our sentence, we see that "which contributes to its depletion by being overfished" refers to monkfish … so monkfish are contributing to their own depletion. That doesn't make much sense. We can eliminate C, leaving us with A as the correct answer.

We actually featured this problem recently on the PrepScholar GMAT blog as one of the 5 Hardest Sentence Correction Questions. I recommend checking out the article for more strategies and trends we can take away from this and other 700+ level problems!