单项选择题

听力原文：W: Friendship Department Store. May I help you?
M: Yes, could you tell me when the store closes today?
W: We close at 7:30.
M: I see. And when do you open?
W: Nine o'clock on the weekend.
M: Fine. Thank you very much.
What's the probable relationship between the two speakers?
A．Receptionist and customer.
B．Waitress and customer.
C．Salesperson and customer.
D．Nurse and patient.