The doctor cheaked over the crying baby again and again,but still couldn't find out ? with it.

A,这个前面是过去时所以后面从句用过去时，而what was the matter with it就是从句的正确语序。很多人都会觉得B也是陈述语序而选B，但是你要注意了，这个题考的就是这个，What‘s wrong,What's the matter 在宾语从句里就是这个语序，不是B项的语序。