—Be quick please. I have to be there by 9:00— but I’ll try my best.A. That’s all rightB.

问题补充：

—Be quick, please. I have to be there by 9:00

—, but I’ll try my best.

A. That’s all right

B. No problem

C. I can’t promise

D. It’s impossible

答案：

A. That’s all right

B. No problem

C. I can’t promise

D. It’s impossible

解析：由but可知我会尽力的，但不一定能保证你按时到那儿。故选C。