TTGWD2-1感觉A不对,但不知道为什么

Q1:

Neither First Lady Eleanor Roosevelt nor Secretary of Labor Frances Perkins sought recognition by the press, and both cautiously allowed others of the Roosevelt brain trust to take credit for the genesis of historic programs in public employment, relief, and social security that were in large measure what they had been responsible for.

1. to take credit for the genesis of historic programs in public employment, relief, and social security that were in large measure what they had been responsible for
2. to take credit for the genesis of historic programs in public employment, relief, and social security for which the two women were in large measure responsible
3. taking credit for the genesis of historic programs in public employment, relief, and social security for which the two women were in large measure responsible
4. taking credit for the genesis of historic programs in public employment, relief, and social security that were in large measure what they were responsible for
5. taking credit for the genesis of historic programs in public employment, relief, and social security which were largely their responsibility

顶一下

选B   

A  what they had been 累赘  ， they指代不清

A.to take credit for the genesis of historic programs in public employment, relief, and social security that were in large measure what they had been responsible for

A is wrong for at least two reasons:

1. "they" refers to who?

2. "had been" means they were "not responsible" any more.  Hence, the logical meaning is wrong.

噢,我明白了.

我竟然忽略了这么优先的时态

C为什么不对呢? B和C只有 to take和taking 的区别

大牛指点

看不到啊

有同樣的疑惑，堅持B對

我拿到的答案的版本是C。。。