OG中一道题，看了解释还是没有明白

liuxuejunjx

230.
In an effort to reduce their inventories, Italian vintners have cut prices; their wines have been priced to sell, and they are.
(A) have been priced to sell, and they are
(B) are priced to sell, and they have
(C) are priced to sell, and they do
(D) are being priced to sell, and have
(E) had been priced to sell, and they have
OG解释
In choice C, the best answer, do is correctly used in place of the full verb do sell; in this verb, do is a conjugated form and sell is in the infinitive form, corresponding to its previous use in the sentence (in the phrase priced to sell). In choice A, the omitted word is selling; in B, D, and E, it is sold. Neither of these forms corresponds properly to to sell earlier in the sentence. Also, in E, the past perfect had been priced signifies that the wines had been priced to sell before the prices were cut.
要点：此题非常难以理解，只能记忆加理解
这个句子的最后一个部分没有弄清楚，在这里and they/are/do/have翻译起来是什么意思啊
答案为C，没有想明白为什么
这里也很难判断用一般时还是完成时。

ecsniffer

这里的do代替sell