听力原文：M: Five airmail stamps and three regular sta

听力原文：M: Five airmail stamps and three regular stamps, please.

W: Here you are. That will be one dollar and eighteen cents.

Where did the conversation take place？

A．At the bank.

B．In the restaurant.

C．At the post office.

请帮忙给出正确答案和分析，谢谢！