问题补充：
Mother asked the youngest kid with his toy car．
A. what the matter was
B. what was the matter
C. what the matter is
D. what is the matter
答案：
A. what the matter was
(答案→)B. what was the matter
C. what the matter is
D. what is the matter
解析：考查名词性从句的语序问题。在所有的名词性从句中，都要使用陈述语序，在该结构：what is the matter?中主语就是what，表语即为the matter。故变成陈述句时，仍然为该语序。
