听力原文：M: Could you give me something for the pain？ I didn't get to sleep until three o'

W: Aspirin is the strongest medication I can give you without a prescription.

M: That isn't strong enough, and I don't have an appointment with my dentist until next week.

W: Who is your dentist？

M: Dr. Williams.

W: Doesn't he have his office on the corner？

M: Yes, he does.

W: Are you a regular patient？

M: Yes.

W: Oh. Then I can call him if you like. Dr. Williams will give me a pain prescription over the phone.

M: I'd appreciate that very much. Do you think that he'll still be in his office？

W: Sure. It's only four-thirty. He should be there until five.

M: Good.

W: Too bad you can't get an appointment sooner.

M: I know. Dr. Williams is always booked up though. I was lucky to get in as soon as I did.

W: In the mean time, be careful not to eat or drink anything too hot or too cold.

M: I really don't feel like eating or drinking anything at all.

W: Well, I'll give Dr. Williams a call and we'll see what we can do for you.

Where did this conversation most likely take place？

A．At the dentist's.

B．In a drug store.

C．In a hospital.

D．At a school clinic.