请教一道语法题

Byron possessed powers of observation that would have made him a great anthropologist and that makes his letters as a group the rival of the best novels of the time.

(A) makes his letters as a group the rival of

(B) makes his letters as a group one to rival

(C) makes his letters a group rivaling

(D) make his letters as a group the rival of

(E) make his letters a group which is the rival of

答案是D，为什么不是E？

as a group修饰letters, 整个make+n1+n2的句型：n1是"his letters as a group"，n2是"the rival of..."

ps:lz发贴时在标题里尽量标出题号哦，这是语法大全里的题目

make his letters，as a group, a rival...

这样是不是清楚一点。

是make his letters a rival,而不是make his letters as a group,

as a group 修饰 letters