有关鼓室肌生理功能的描述哪项正确（）

A.主要生理功能为保护内耳免受损害

B.控制咽鼓管开闭

C.鼓膜张肌收缩增加鼓膜张力

D.鼓室肌具有保持内毛细胞张力的作用

E.镫骨肌收缩可减少内耳压力

-- Haven’t I told you to prepare your lessons well before the exam? You failed again.

-- But I ______ for the exam longer than I usually do.  [ ]

A. was preparing

B. will prepare    

C. have prepared  

D. prepared