When Jane fell off the bike, the other children ________.

When Jane fell off the bike, the other children ________.
A、were not able to help laughter
B、could not help but laughing
C、could not help laughing
D、could not help to laugh
【正确答案】：C
【题目解析】：固定搭配。can not help but do sth．表示“禁不住做某事”。