— Could I talk to Prof. Lee? — _________________. Oh, it's you B; Yes, speaking C; I'm wai

— Could I talk to Prof. Lee? — _________________. Oh, it's you B; Yes, speaking C; I'm waiting for youA:

The question tests common telephone conversation responses. When someone asks to speak to a specific person and you are that person, the standard reply is "Yes, speaking" to confirm your identity.

B; Yes, speaking

This response directly acknowledges that the caller has reached the intended person (Prof. Lee). Option A ("Oh, it's you") would only be appropriate if you recognized the caller's voice immediately, which isn't indicated here. Option C ("I'm waiting for you") is irrelevant to the context of answering a call.