Jean didn’t have time to go to the concert last night because sh

Jean didn’t have time to go to the concert last night because she was busy ______ for the examination.
A、to prepare
B、to be prepared
C、preparing
D、being preparing
【正确答案】：C
【题目解析】：本题考查be busy doing为习惯用法，表示：忙于做什么。句中意思为Jean因忙于准备考试，故昨晚没时间去听音乐会。