This is a SC question from the OG. I know that because I've only just finished it!

The correct idiom is as many.... as. This is why choices A, C and E are incorrect.

The problem with choice B is that it compares taxpayers with the Tax Reform Act. Besides, placing at once immediately after confronting distorts meaning: it makes it sound like taxpayers confronted something at once (i.e. right away); that "at once" is used to describe the fact that the changes occurred at the same time.

This is why choice D is correct: it respects the idiom and it compares taxpayers with taxpayers.

figs wrote:Never before had taxpayers confronted so many changes at once as they had in the Tax Reform Act of 1986.
A. so many changes at once as they had in
B. at once as many changes as
C. at once as many changes that there were with
D. as many changes at once as they confronted in
E. so many changes at once that confronted them in

OA:D

Figs,
PLEASE UNDERLINE THE SC sentences that may REQUIRE any CHANGE