主诉牙应是

A．右下第一前磨牙

B．右下第二前磨牙

C．右下第一磨牙

D．右下第二磨牙

E．右下第三磨牙

—What did you say to your sister? I saw her crying in the room.

— It _________ my fault. I just said hello to her when I met her, nothing else.

A．must have been

B．can’t have been

C．oughtn’t to be

D．should have been