Could you come to my house for dinner this Saturday?(单选)

问题描述:

Could you come to my house for dinner this Saturday?(单选)
—Could you come to my house for dinner this Saturday?
—I'm sorry,_____I have to go to a meeting.
A.and
B.but
C.although
D.so

A 表示并列(B‘转折’C ‘虽然’D,所以,这三项与句意不符)