—Hey，you haven't been acting like yourself．Everything is OK?
— .
A. Sure, it is
B. I'm fine，thanks
C. That's good
D. It's a pleasure
网友回答
A. Sure, it is
(答案→)B. I'm fine，thanks
C. That's good
D. It's a pleasure
解析：交际用语。回答对方所问：Everything is OK? B符合要求。