听力原文：M: Good morning. Is this where we should come to add or drop a course？
W: Yes, it is. Just write the name of the course you want to drop on this blue form.
M: Great! So where do I write the name of the astronomy course that I want to add？
W: Sorry, it's too late to add a course. You should only add courses two weeks into this semester. And Friday was the last day.
M: But I'm a senior. And if I dropped the class and couldn't add in, I wouldn't have enough credits to graduate.
W: So, what you have to do then is to get the professor's approval and have him sign the special add form. Then bring it back to me, and I put it to through.
M: Okay. Thanks, I hope I'll be able to find the right person.
(20)

A. How to drop a course.
B. The man needs advice about which classes to take.
C. How to get the approval of the professor.
D. How to add a course to the man's schedule.