I’m pretty sure that the answer is A. When people are arguing they give reasons of why they’re right, so I would think it’s A. Hope this helped, and sorry if I’m too late!! :D
The answer is D because it states an hypothetical situation, as you explained above.
Nick has a lunch with Gatsby and Wolfshiem is there. He mentions to Nick that<span> he is a gentleman of
“good breeding,” not the type to go after anybody’s wife or anything</span>