Explanation
Correct answer: D.
Choice D is the best answer. The clause before the colon tells us that the novel “asks a question,” so the clause after the colon should be in the conventional form of a question: with the verb before the subject, and a question mark at the end.
Why the other choices are wrong
Choice A
Choice A is incorrect. This choice ends the sentence with a period, which isn’t right. The clause before the colon tells us that the novel “asks a question,” so the clause after the colon should be that question.
Choice B
Choice B is incorrect. This choice ends the sentence with a period, which isn’t right. The clause before the colon tells us that the novel “asks a question,” so the clause after the colon should be that question. In Standard English, questions place the verb before the subject and end with a question mark.
Choice C
Choice C is incorrect. This choice doesn’t conform to the conventions of Standard English. In Standard English, questions place the verb before the subject.