I kinda hate this question. And I swear that I’m basically a very happy person.

Quote:
(A) extinction; its numbers are now five times greater than
Two things jump out at me right away in (A), and neither of them are a problem. First, the semicolon needs to separate two independent clauses, and it does exactly that. Second, the “its” needs to refer back to a singular noun, and it does exactly that – “its” refers to “the gyrfalcon.”
So I wouldn't eliminate (A) right away. But it is awfully similar to (B), so let’s put them side-by-side:
Quote:
(A) extinction; its numbers are now five times greater than
(B) extinction; its numbers are now five times more than
The only difference is that (A) uses the phrase “greater than”, and (B) uses “more than.” In real life, I don’t think that either of these necessarily sounds better than the other, and I probably wouldn't notice if somebody said the incorrect version.
Here’s the thing: if you’re comparing numbers themselves – not quantity in general, but actual numbers – it’s generally better to use “greater than” instead of “more than.” For example, you would read the mathematical expression 20 > 10 as “twenty is
greater than ten.”
Or you consider the following two sentences:
- I ate more burritos than Mike last night. → we’re comparing quantities of burritos in general, not the numbers themselves, so “more” is OK
- I ate a greater number of burritos than Mike last night. → now that we’re comparing the numbers, we need to use “greater”
- I ate a more number of burritos than Mike last night. → not remotely tempting to use “more” to compare the numbers themselves in this case, right?
Back to the GMAT question. Since we’re directly and literally comparing the
numbers themselves, we need to use “greater than”, and not “more than”.
So we can eliminate (B), and hang onto (A).
Quote:
(C) extinction, their numbers now fivefold what they were
Hopefully, the pronouns jump right off the page at you. “Their” needs to refer to a plural noun, and… well, we don’t have any plurals earlier in the sentence. “The gyrfalcon” is singular.
So (C) is out.
Quote:
(D) extinction, now with fivefold the numbers they had
(D) has a similar problem as (C): there’s some general awkwardness, but the much more important issue is that “they” doesn’t have a logical referent. The only plural noun earlier in the sentence is “the numbers”, and that definitely wouldn’t work: “… now with fivefold the numbers the numbers had…” Yikes. Of course, “they” is logically trying to refer to “the gyrfalcon”, and that’s singular.
So (D) is gone, too.
Quote:
(E) extinction; its numbers are now five times greater than what they were
(E) is just a crappier version of (A). The only real difference is that (E) adds the phrase “what they were” to the end of the sentence, and there’s no good reason to do that – it adds nothing to the meaning, and just makes the sentence wordier and messier.
We can eliminate (E), and (A) is the best we can do.
Thank you GMATNinja, but I am positing that A is incorrect (not just more concise). A has an incorrect parallelism issue. It would have to read: "extinction; its numbers are now five times greater than
.... Otherwise, it incorrectly compares "its numbers" with "when the use of DDT was sharply restricted." Am I reading this incorrectly? Would love souvik101990 to weigh in with the source of this Q and reasoning behind OA. I always find it strange when the data reveals overwhelming support for a "wrong" answer (49% chose E vs. 34% for A).