再次求助？？？？

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

答案为什么是D,那个the rival of 为什么能和a group连在一起？

1，make (his letters as a group) the rival of 

是 make A B结构

2，用排除法也只能选D了

民白了，谢谢