Only then________ realize that we had wronged him.   [ ]

A. we came to        

B. did come we to    

C. we did come to      

D. did we come to

患者男性，45岁。原发性肺动脉高压伴严重低氧血症及心衰的终末期支气管肺疾患，行心肺联合移植术。入手术室心率120次/分，血压110/70mmHg，PaCO₂55mmHg，Pa0₂75mmHg。

该患者室扑、室颤的发生原因最可能是（）

A.严重高血压

B.严重呼吸功能不全

C.严重低血钾

D.严重低血钙

E.严重冠状动脉供血不足