The boss refused to sell the car for he thought was not satisfactory A. thatB. which C.

问题补充：

The boss refused to sell the car for he thought was not satisfactory,

A. that

B. which

C. how

D. what

答案：

A. that

B. which

C. how

(答案→)D. what

解析：句意：那位老板拒绝以不满意的价格卖车。这里he thought为插入语，what作宾语从句的主语