Lee isn't in the classroom.i am sure he ____be on the play-ground now.A can B may C must D should

Lee isn't in the classroom.i am sure he ____be on the play-ground now.
A can B may C must D should

B may be 是可能的意思 用在句中间

既然使用了 Sure 则说明 I 肯定知道Lee 在什么地方。所以，答案 C 是正确的。