请选择ABCD;d/d5u3e-y2Y/H(^8k/w1Y:y —I wonder why Mr.Green looks quiet in class.9f6W,m
—I’m not sure，but he_________ a small accident driving here.9f6W,m
A.could have9f6W,m
B.might have9f6W,m
C.might have had9f6W,m
D.must have had9f6W,m