问一道高二英语虚拟语气选择题目

题目

问一道高二英语虚拟语气选择题目
_________________,George would certainly have attended the conference.
A if he didn't get a flat tire
B if the flat tire hadn't happened.
C had he not had a flat tire
D had the tire not flattened itself
麻烦告诉一下为什么,

答案

c对过去情况的虚拟,a错
c省略了if
原句：If he hadn't had a fire tire,.
b、d的话tire作主语没用被动,所以错了