gmatprep的题目，请大家帮忙

Because she knew many of the leaders of colonial America and the American Revolution personally, Mercy Otis Warren was continually at or near the center of political events from 1765 to 1789, a vantage point combining with her talent for writing to make her one of the most valuable historians of the ear

(a)    a vantage point combining with her talent for writing to make

(b)    a vantage point, when combined with her talent for writing, that made

(c)    a vantage point that combined with her talent for writing, and it made

(d)    and this vantage point, which combined with her talent for writing to make

(e)    and this vantage point, combined with her talent for writing, made

答案选E，B为什么错误？

1. a 是泛指，this是特指.

作者讲了半天，就是要你承认 this vantage point (= MOW was ... to 1789)很有决定意义。

2。B 中的when多余。

不同意第一点。a vantage point that... 是同位语修饰1765 to 1789。见OG43, an obscure and unimaginable place that...

同意第二点。

确实看到过很多同位语用的是 a +n + that，关于这点疑问还行牛人考证

谢谢joe11和jandjshi