Dear Friends,
Here is a detailed explanation to this question-
hoogie wrote:
Unlike the short flights of the shuttle and earlier spacecraft, which carried sufficient power in fuel cells and batteries, a permanently orbiting space station will have to generate its own electricity.
A. the short flights of the shuttle and earlier spacecraft, which carried sufficient power in fuel cells and batteries
B. the shuttle and earlier spacecraft, with sufficient enough power in fuel cells and batteries for their short flights
C. the short flights of the shuttle and earlier spacecraft, which enabled them to carry sufficient enough power in fuel cells and batteries
D. the shuttle and earlier spacecraft, which were capable of carrying sufficient power in fuel cells and batteries for their short flights
E. the flights of the shuttle and earlier spacecraft, whose shortness allowed them to carry sufficient power in fuel cells and batteries
Meaning is crucial to solving this problem:Understanding the intended meaning is key to solving this question; the intended meaning of this sentence is that the shuttle and earlier spacecraft were capable of carrying sufficient power in fuel cells and batteries for their short flights and are unlike a permanently orbiting space station, it that it will have to generate its own electricity.
Concepts tested here: Meaning + Modifiers + Comparisons• A comparison must always be made between similar things.
• "who/whose/whom/which/where", when preceded by a comma, refer to the noun just before the comma.
A: This answer choice incorrectly modifies the noun phrase "the short flights...spacecraft" with "which carried...and batteries", illogically implying that the flights of the shuttle and earlier spacecraft carried enough power in fuel cells and batteries for some unspecified purpose; the intended meaning is that the shuttle and earlier spacecraft were capable of carrying sufficient power in fuel cells and batteries for their short flights; please remember, "who/whose/whom/which/where", when preceded by a comma, refer to the noun just before the comma. Further, Option A incorrectly compares "the short flights" to "a...space station"; please remember, a comparison must always be made between similar things.
B: This answer choice uses the redundant phrase "sufficient enough", rendering it awkward and needlessly wordy; this phrase is redundant, as both sufficient and "enough" convey a sense of sufficiency.
C: This answer choice incorrectly modifies the noun phrase "the short flights...spacecraft" with "which enabled...and batteries", illogically implying that the flights of the shuttle and earlier spacecraft allowed them to carry enough power in fuel cells and batteries for some unspecified purpose; the intended meaning is that the shuttle and earlier spacecraft were capable of carrying sufficient power in fuel cells and batteries for their short flights; please remember, "who/whose/whom/which/where", when preceded by a comma, refer to the noun just before the comma. Further, Option C incorrectly compares "the short flights" to "a...space station"; please remember, a comparison must always be made between similar things. Additionally, Option C uses the redundant phrase "sufficient enough", rendering it awkward and needlessly wordy; this phrase is redundant, as both sufficient and "enough" convey a sense of sufficiency.
D: Correct. This answer choice correctly modifies "the shuttle and earlier spacecraft" with "which were capable...their short flights", conveying the intended meaning - that the shuttle and earlier spacecraft were capable of carrying sufficient power in fuel cells and batteries for their short flights. Further, Option D correctly compares "the shuttle and earlier spacecraft" and "a...space station". Besides, Option D is free of any awkwardness or redundancy.
E: This answer choice incorrectly modifies the noun phrase "the flights...spacecraft" with "whose shortness enabled...and batteries", illogically implying that the flights of the shuttle and earlier spacecraft allowed them to carry enough power in fuel cells and batteries for some unspecified purpose; the intended meaning is that the shuttle and earlier spacecraft were capable of carrying sufficient power in fuel cells and batteries for their short flights; please remember, "who/whose/whom/which/where", when preceded by a comma, refer to the noun just before the comma. Further, Option E incorrectly compares "the flights" to "a...space station"; please remember, a comparison must always be made between similar things.
Hence, D is the best answer choice.To understand the concept of "Which/Who/Whose/Where" on GMAT, you may want to watch the following video (~1 minute):
All the best!
Experts' Global Team