The correct answer is B. he has big parties but few friends.
Paradox occurs when you expect one thing to happen, but actually the opposite happens. So, when Gatsby throws so many parties, we expect that he has a lot of friends and that people generally love him. However, the opposite is true - he doesn't have many friends at all, if any. Nick could maybe be considered a friend of his, and that would be pretty much it.
So it is paradoxical that even though he is so famous, he doesn't have anyone close to him despite his popularity.
Similes use the words like or as to compare things—“Life is like a box of chocolates.” In contrast, metaphors directly state a comparison—“Love is a battlefield.”
