-Thanks for your help,but can you do me one more favor ,please?-_D_ ,sir.What's it then?

问题描述:

-Thanks for your help,but can you do me one more favor ,please?-_D_ ,sir.What's it then?
C.That's all right D.At your service
为啥不选C

D 乐意为您效劳,服务用语啊