the same as 这个句子的机构对吗

OG 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（D）

(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.

the past perfect had [confronted] illogically places the 1986 events in the same time frame as
            Never before had...;

这个OG的解释的句子的比较对吗？Never before had作什么成分，什么成分之间的比较呢？

请NN指教。

还是有点不明白，能否将这个句子补全呢，谢谢JAMES