made things worse Peter said was that his parents stopped supporting him in developing

问题补充：

made things worse, Peter said, was that his parents stopped supporting him in developing the “flying car”.

A. It

B. Which

C. As

D. What

答案：

A. It

B. Which

C. As

(答案→)D. What

解析：考查what引导的主语从句，what在主语从句中做主语，Peter said是插入语，句意：皮特说：使事情更糟糕的是父母不再支持他的飞车。选D。