听力原文：W: Hi, Mark, how is it going？
M: Well, not so great.
W: What's wrong？
M: I've got a big problem with the poetry course that's required for my major.
W: Is that all filled up？
M: No, no, there's plenty of room, but there is a prerequisite. I've got to take an introduction to poetry before I can take the special course in poets of the 1960's, and the introductory course is only offered in the evening.
W: You don't like evening classes？
M: No, that's not the point, I work in the cafeteria every evening, I need the money to pay for my tuition.
W: Can you ask someone at work to switch hours with you？ Maybe you could just switch a couple of evenings since the course probably only meets two times a week.
M: I wish I could. My boss just did me a favor by putting me on evenings. And he'll hit the ceiling if I ask him to change again.
W: Wait a minute. I have an idea. Have you checked the courses over at the community college？ They might offer an introductory poetry course during the day.
M: Hey, that's a great idea, I'm free this afternoon. I think I'll go over and check it out. Yeah, their courses are actually cheaper, and you can transfer the credits over there. Thanks for the advice, Linda. I'll let you know what happens.
W: Sure, Mark. Good luck. Oh, while you are there, could you find out when their pool is open？
M: No problem!
What prevents the man from taking the poets of 1960's class？

A. It's only open to poetry majors.
B. It's requires another class tirst.
C. It's already full.
D. He wants to have a rest.