My parents used they had to get a new car for my brother.A. whichB. all whatC. whatD. 不填

问题补充：

My parents used they had to get a new car for my brother.

A. which

B. all what

C. what

D. 不填

答案：

A. which

B. all what

(答案→)C. what

D. 不填

解析：句意，我的父母用他们所拥有的东西为我的哥哥买了一辆新的汽车。分析句子结构，从句是以what引导的宾语从句，意为所…的东西。