Question #N1291
The scientist, Dr. Elena Ortiz, has been studying the effects of exercise on the brain. She hopes to eventually understand how working out can make people smarter.
Which choice completes the sentence so that it conforms to the conventions of Standard English?
A. Dr. Ortiz, hopes to eventually understand how working out can make people smarter.
B. Dr. Ortiz hopes, to eventually understand how working out can make people smarter.
C. Dr. Ortiz hopes to eventually understand how working out, can make people smarter.
D. Dr. Ortiz hopes to eventually understand how working out can make people smarter.
Correct Answer is: D
The correct answer is D. The phrase "to eventually understand how working out can make people smarter" is a nonessential element in the sentence. We need a comma to separate it from the rest of the sentence. Choice A is incorrect because no punctuation is needed before a nonessential element. Choice B is incorrect because no punctuation is needed after a nonessential element. Choice C is incorrect because a comma can’t be used to separate a nonessential element from the rest of the sentence.