单项选择题
A: Haven't we met somewhere B: No, I don't think so. A: Aren't you Kevin Grant B: No. No, my name's Greg. Greg Brown. A: ______.
A．I've had enough, thank you.
B．I'm sorry, but I've got nothing to let.
C．Oh, I'm sorry. I was positive we'd met before.
D．I think otherwise.