Based on the context of the conversation, here are the suggested answers:

For question 15:
- A: "Do you mind turning on the air conditioner for me?"
- B: "C. No, not at all."

For question 16:
- Ann: "Would you like me to get a taxi for you?"
- Jimmy: "B. A taxi can get stuck in traffic congestion."

So the correct answers are:
- 15: C
- 16: B