Had he worked harder, he __________ the exams.
A) must have got through B) would have got through
C) permitted are freshmen D) are permitted freshmen
B
看题目，前半句为倒装，还原为：
If he had worked harder
什么语气啊？虚拟！是对现在、过去还是将来的虚拟？过去！
IF条件从句用had done, 主句用would(could,should,might)+have done
选B