肩周炎的病因不包括下列哪项（）

A.肩部慢性劳损

B.肩部急性外伤

C.肩部受凉

D.冠状动脉供血不足

E.感染或活动减少

John ___ such a thing about you. He never speaks ill of you behind your back.[ ]

A. can't have said        

B. might not have said

C. couldn't say          

D. mustn't have said