Woman: Ed, how is your swimming class going？ I think you are learning well. Man: Slowly bu

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！