“Constance Culmington, he reflected to himself, was exactly the sort of woman who would buy an island and surround herself with mystery! Nodding his head in gentle approval of his logic, Mr. Justice Wargrave allowed his head to nod... He slept..." Chapter 1, pg. 3
Rhetorical questions add a level of cheesiness to the paper and unless you are a very good writer, and I mean college professor level, then you will most likely fail at any attempt. Also writing research papers your suppose to be telling the reader what they don't know instead of asking them what is already do know.
Answer: Which (A)
It makes more sense with ‘which’ then any of the other options.
My guess would be each quatrain develops the problem of the poem and<span>the turn (volta<span>) comes at the beginning of the closing couplet.</span></span>