— There were already five people in the car but they managed to take me as well .
— It a fortable journey .
A. can''t be
B. shouldn''t be
C. mustn''t have been
D. couldn''t have been
网友回答
A. can''t be
B. shouldn''t be
C. mustn''t have been
(答案→)D. couldn''t have been
解析：对过去推断要用“情态动词+have +p . p”结构。C项中 must 不能用于否定。