OG SC 92

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

Choice D is the best answer, stating grammatically and clearly that, with the 1986 Tax Reform Act, taxpayers confronted more simultaneous changes than ever before. In choice A, the past perfect had [confronted] illogically places the 1986 events in the same time frame as Never before had...; a simple past tense is needed to present the 1986 events as following the earlier ones. Choices B and C awkwardly place at once between confronted and its direct object, changes. Furthermore, B illogically states that the Act itself was many changes, when the point is rather that it presented many changes, and as many ... that is an unidiomatic comparison. Choice E, too, presents an unidiomatic comparison with so many... that.