A、ballet. B、Swimming. C、Nursing. D、Teaching B对话中明确谈到Cathy喜欢游泳，芭蕾是母亲让学的她并不喜欢，而C、D两项对话中未提及，故应选B。

M: There are just one or two more things, Catherine.
W: Do call me Cathy.
M: OK, Cathy. Are you really interested in being a vet?
W: Not really. Anyway, I’m not bright enough. I’m reasonably intelligent, but I’m not brilliant, I’m afraid my mother is a bit over optimistic.
M: Yes, I guessed that. She’s a bit overpowering, isn’t she, your mum?
W: A bit. But she’s very kind.
M: I’m sure she is. So, you’re interested in ballet and music, are you?
W: Not really. My mother sent me to lessons when I was six, so I’m quite good, I suppose. But I don’t think I want to do that for the rest of my life, especially music. It’s so lonely.
M: What do you enjoy doing?
W: Well, I like playing tennis, and swimming.  Oh, I went to France with the school choir last year. I rosily enjoyed that. And I like talking to people. But I suppose you mean real interests things that weald help me to get a jab?
M: No. I’m more interested in what you really want to do. You like talking to people, do you?
W: Oh yes, I really enjoy meeting new people.
M: Do you think you would enjoy teaching?
W: No, no, I don’t really. I was never very interested in school work, and I’d like to do something different. Anyway, there’s a teacher training college very near us. It would be just like going to school again.