Dr. Hampton: Good morning. Professor Smith. Professor Smith:______, Dr. Hampton.Dr. Hampto

Dr. Hampton: Good morning. Professor Smith. Professor Smith:______, Dr. Hampton.Dr. Hampton: May I come in？Professor Smith: Of course, please.

A．Good morning

B．Fine, thanks

C．Pleased to meet you

D．How do you do

请帮忙给出正确答案和分析，谢谢！