【请教prep一道语法题！~~】

水色青空

142.(32496-!-item-!-188;#058&006253)

According to a 1996 study published in the Journal of Human Resources, Americans of Middle Eastern descent were twice as likely as was the national average to be self-employed.

(A) as was the national average to be self-employed

(B) as the average American to be self-employed

(C) as the national average that they would be self-employed

(D) to be self-employed than was the average American

(E) that they would be self-employed than was the national average

答案选B，这题考了省略结构，我想请问一下A选项是如何排除的？另外，为什么A中的was可以省略？有没有人能还原一下这个句子？。。。。
万分的感谢~~~

水色青空

顶一下~~

jinghe

比较的前后必须概念相等, as likely as 前说的是Americans of Middle Eastern descent, 是noun, 所以as likely as 后也必须是一个概念相等的东西来进行比较, average American 符合要求, 前后都是人和人的比较,所以选B. A 答案中把 national average 和Americans of Middle Eastern descent 进行比较, 是不正确的.