单项选择题

[听力原文]6-7
M: Will you please show me that notebook
W: Certainly.
M: How much is it
W: Twenty-one yuan and fifty fen.
M: Hm. It’s certainly nice, but it’s a bit more than I was thinking of paying. I don’t think I’ll take it.
W: How about that size It’s also very good and much cheaper.
M: Let me see one.
W: This size is ten yuan and ninety fen.
M: That’s very reasonable. I’ll take it then.

What’s the probable relationship between the two speakers()

A.Lawyer and client.
B.Student and teacher.
C.Shop assistant and customer.
D.Manager and employee.