did you know that David injured his leg yesterday? – really? （）

did you know that David injured his leg yesterday? – really? （）
A.Who did that?
B.What’s wrong with him?
C.How did that happen?
D.Why was he so careless?
正确答案：C.
解析: 问：你知道David昨天伤到腿了吗？答：真的吗？怎么回事？