In the sentence below, why did the man feel foolish?

“It had been a foolish whim to come at all—foolish, because the object of his quest was not to be found there or elsewhere.”

A He realizes that he cannot solve his problems by coming home.
B He finally understands that coming home was a mistake.
C He discovers that his home is not as wonderful as he had thought.
D He believes that his life is better now than when he was young.