D. Men in this culture are more skeptical than women.
Ok it is definitely not C. because that is not supposed to be the point in the quote. Also it is not B. that is not the main point either.
It is not A. either because that is an opinion
Ok look at this quote: "'That's just like you men; you don't believe in anything.'"
Skeptical means they are harder to convince and don't believe in things as easily. (D. Men in this culture are more skeptical than women. )