Speaker A: Excuse me, Professor Smith, can you spare me a few minutes There' s something I'd like to speak to you about. I won' t keep you long.Speaker B:______ A．Of course not. Haven' t you seen have been pretty busy nowB．Well, I'm afraid we have to find some other time. I' m fully occupied now.C．No. I'll have an important meeting to attend this evening.D．Not possible, as I don't know how long you will keep m