He gets fifty thousand pounds a year I get twenty million which makes me upset.A. sinceB

问题补充：

He gets fifty thousand pounds a year I get twenty million, which makes me upset.

A. since

B. while

C. when

D. as

答案：

A. since

(答案→)B. while

C. when

D. as

解析：while位于两个并列分句的中间，侧重两个动作的对比。