What is the purpose of this conversation?

Man: Dr. Kelly, do you have a minute?
Woman: Sure. Come in.
Man: Thanks. I need to talk with you about my sociology class.
Woman: Let’s see, that would be Sociology 530 with Dr. Brown.
Man: Right. The problem is that when I scheduled that class, it was supposed to be offered at three o’clock in the afternoon, Tuesdays and Thursdays, but for some reason the time has been changed to nine in the morning. Since I work mornings, I can’t take it at that time.
Woman: I see. Well, would you like to drop the class?
Man: Yes, but I also need to pick up another class. I have to be a full-time student in order to qualify for my student loan.
Woman: So you need at least twelve hours. And you need afternoon classes.
Man: That’s right. Or evening classes.
Woman: Did you have anything in mind?
Man: Yes. I was considering Sociology 560 or 570. I thought I’d get your opinion.
Woman: Either one will fit into your program since you are a Sociology major, and they are both electives. Too bad you can’t get a compulsory course.
Man: I know, but they all seem to be offered in the morning.
Woman: Okay, then. Which one is the most interesting to you?
Man: I’m interested in both of them, but I was thinking since Dr. Brown teaches Sociology 560, I might prefer that one. I’ve been trying to take a class with her because I hear that she is an excellent professor.
Woman: Good. The class is open, and I’ll just sign that drop-add form for you to drop 530 and add 560. You can just tell Dr. Brown what happened when you see her in class.
Man: Okay. Thanks a lot, Dr. Kelly. I really appreciate it.
Woman: Don’t mention it.