In a process that has become de rigeur following the end of

its idiom error...the ' so much' should carry 'as'

Since the abovementioned sentences are talking about libraries, so eliminate options with "it"

In a process that has become de rigeur following the end of every presidency, presidential libraries are sprouting up like carbuncles all over the land, testifying not so much to a sense of history among our politicians than it reflects their unbridled vainglory.

POE:
Eliminate (A), (B) &(C) -'it' is ambiguous.
Eliminate (D) - 'Not so much' is the correct idiom

A) testifying not so much to a sense of history among our politicians than it reflects their
B) testifying less to a sense of history among our politicians than it reflects their
C) not so much testifying to a sense of history among our politicians as it reflects their
D) testifying not as more to a sense of history among our politicians than to an
E) testifying not so much to a sense of history among our politicians as to their -CORRECT

Hello from the GMAT Club VerbalBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.