Official ExplanationSome wildlife managers recognize that the impact on human activity apparent in New York’s deer population is the result of "deer overabundance "-
at some time in the past the deer population exploded, significantly increasing their numbers and hence our deer population predicament.
A. at some time in the past the deer population exploded, significantly increasing their numbers B. that at some time in the past the deer population exploded that significantly increased their numbersC. that sometime in the past the deer population exploded so that their numbers were significantly increasedD. some time in the past the deer population exploded from which their numbers were significantly increasedE. some time in the past the deer population exploded so as to increase their numbers significantly,This question deals with parallelism. Since “that” is used at the beginning of the sentence in the phrase “that the impact,” it should also be used at the beginning of the explanation after the dash, “- that.” The end of the sentence also needs to be parallel. “Our deer population,” uses the format pronoun + noun, so the phrase before should read “their numbers,” to make it parallel. Differences within the text are highlighted.
A. at some time in the past the deer population exploded, significantly increasing their numbersThis is
INCORRECT. The beginning of this portion of the sentence does not start with “that,” so it is not parallel with “that the impact.” It does get the “their numbers” portion correct, but that’s not enough to make this our correct choice.
B. that at some time in the past the deer population exploded that significantly increased their numbersThis is
CORRECT. This sentence is parallel with the use of “that.” The end of the sentence uses a pronoun + noun, “their numbers,” and “our deer population,” making it parallel as well.
C. that sometime in the past the deer population exploded so that their numbers were significantly increasedThis is
INCORRECT. While the first portion of this sentence is parallel with the use of “that,” there is an issue later; “were significantly increased,” is not parallel with the end of the sentence, “our deer population predicament.” To be parallel, it should be pronoun + noun.
D. some time in the past the deer population exploded from which their numbers were significantly increasedThis is
INCORRECT. The beginning of this portion of the sentence does not start with “that,” so it is not parallel with “that the impact.”
E. some time in the past the deer population exploded so as to increase their numbers significantly,This is
INCORRECT. The beginning of this portion of the sentence does not start with “that,” so it is not parallel with “that the impact.”
There you have it - option B is the only one that handles all of the parallelism issues correctly!Don’t study for the GMAT. Train for it.