ziyuen
Last year, fewer
whales than they did before traveled back to their tropical breeding grounds in search of warmer water.
A. whales than they did before
B. whales than there ever were before
C. than ever before, whales
D. than they ever were before, whales
E. whales than ever before
OFFICIAL SOLUTION
You should recognize quickly that this problem deals with comparisons (the word before the underline is "fewer" and multiple answer choices start with the classic comparison signal word "than"). Your job, then, is to ensure that you're dealing with a logical comparison.
Choice A illogically uses "they" as part of the comparison; as a pronoun "they" has to refer back to "whales," but this implies that it was the same whales and not a comparison between the numbers of whales.
Choice B illogically compares the whales who migrated last year to the number of whales that ever existed. Choice D, essentially, combines the mistakes from A and B.
In choice C, the sentence puts "fewer than ever before" in a nonessential modifier. This then modifies "whales" but not as a comparison but rather as a description. As such, this is illogical and strange.
Choice E draws a proper comparison. Fewer whales made the migration this year than ever before. Therefore, choice E is correct.