答案应为C.此句句意为：我在房间睡觉时,一个男孩冲进来了.此句中“sleep"的动作与"rushed" 同时发生,所以应用过去进行时.
又如：The old man fell asleep whie he was watching TV.(老人看电视时睡着了.)
I witnissed a car accident while I was walking in the street.