The answer is:
B. The author evokes sadness at the superficiality of Gatsby's friendships.
In "The Great Gatsby," the author Francis Scott Fitzgerald directs attention to the few friends who attended Gatsby's funeral. In that matter, he gloomily reflects on the fact that Jay used to invite a large amount of people to his prodigious parties at his mansion. However, those frivolous guests who pretended to be his friends do not show up at his burial.