单项选择题
根据各组对话内容，从下面方框里提供的5个选项中选出最佳选项
A: I’m sorry to have kept you waiting for so long.B: （） I’ve been killing time by listening to music.
A．Sure. What is it
B．It’s very nice of you to say so.
C．It’s nothing.
D．Have a nice trip!
E．Certainly. Here you are.