【正确答案】 B

【答案解析】原文：M: Polly, Ms. Kelly has agreed to come and give a talk about international relations next week. When do you think we can fit her lecture in?W: That’s great, Nick. What about Friday afternoon, then?M: I’m afraid some students are planning to go on a trip. Maybe we can have it on Wednesday afternoon.W: No, that’s not possible either. Most students are having group activities for their research projects. Well, I have an idea. I have a class on Tuesday afternoon, and probably Ms. Kelly can use my time.M: That’s possible. But I have to speak to Dr. Li about that, and you should also talk to the students about the change.W: Oh, yes. I’ll certainly do that.