单选题 A：Oh... um... do you mind if I smoke?
B：______.
A：Oh, I didn't notice.
B：Mum. There's a sign on the door.
A. How long for?
B. Well, yes, actually, this is a no smoking compartment.
C. I don't think I agree with you.
D. When exactly?

【正确答案】 B

【答案解析】[解析] B的话是对A的反应，表示自己对于A吸烟的态度问题。B说明了这里是无烟部门，不能吸烟。