Question:
Only one out of every 150,000 chemical compounds proves useful in the field of pharmaceuticals, and thus many research scientists spend their entire careers to investigate drugs that will never receive FDA approval.
Choices:
The original contains a verb tense error: a present participle must follow the subject-verb construction scientists spend. (C) is unnecessarily wordy because it uses arcane language. (D) is incorrect because career should be plural since it refers to careers belonging to "many scientists," and (D) is also unnecessarily wordy because it uses in the investigation of rather than investigating which conveys the same information more concisely. (E) is wrong because there is ambiguity over the antecedent of their.
