We here on time but we were caught in a traffic jam.A. must have arrivedB. could have ar

问题补充：

We here on time but we were caught in a traffic jam.

A. must have arrived

B. could have arrived

C. need have arrived

D. should have arrived

答案：

A. must have arrived

(答案→)B. could have arrived

C. need have arrived

D. should have arrived

解析：B 考察虚拟语气，句义：我们本来能够准时到达，可是我们遇见了交通堵塞了。Could have arrived本来能够到达，却没有到达。符合语境。故B正确。