What a pity. Considering his ability and experience,   he ________ better. [      ]

A. need have done              

B. must have done

C. can have done                

D. might have done

某抑郁症患者，60岁。近1个月来，情绪抑郁，悲观厌世，大便秘结，整日卧床，有心悸。体查：血压90／60mmHg，心电图示二度房室传导阻滞。治疗首选药物（）

A.米帕明

B.氯米帕明

C.多塞平

D.帕罗西汀

E.阿米替林