It was playing computer games that cost the boy plenty of time he doing his lessons.A. m

It was playing computer games that cost the boy plenty of time he doing his lessons.
A. might have spent
B. ought to have spent
C. must have spent
D. could have spent

A. might have spent(答案→)B. ought to have spentC. must have spentD. could have spent解析：本题考查的是虚拟语气的有关用法。Ought to / should + have +p.p表示“本来应该做却没有做到的事情”，有责备的含义。

就是这个解释