Woman: Ed, how is your swimming class going? I think you are learning well. Man: Slowly but surely. Question: What does the man mean?
A.He"s unhappy because he has to go to class.
B.He"s making steady progress.
C.He"s a good swimmer already.
D.He"s sure the class is too slow for him.
请帮忙给出正确答案和分析,谢谢!