First off, the three areas are a, b, and c, so cut D out completely. Next, I've seen people in lots of different types of friendships, it really doesn't matter if you're autistic, or if you're a degenerate, ( sorry for putting so harshly, but needed to think of something fast ) it matters if you're together to be friends, in whatever way possible, so I think the answer is C.Social.
Hope this helps, if not, comment below please!!!