Although many critics are divided on what the actual main dilemma in the poem is, generally it is accepted that the correct answer would be B. he is unable to approach a woman to answer an important question.
He wants to ask a beautiful woman to marry him, because he loves her. However, he is not exactly the most handsome guy ever - he is very thin and balding, so he isn't really attractive. He has qualms about whether to approach the woman because he is afraid of being turned down.
