单项选择题

Speaker A: How do you do? Im pleased to meet you. Speaker B: ______
A.How do you do? Have a good day.
B.I'm fine. It's nice to meet you.
C.How do you do? The pleasure is mine.
D.I'm fine. I'm delighted to know you.

A.How
B.
B.I'm
C.
C.How
D.
D.I'm
E.