5.As tis sales of computer products have surpassed those of measuring instruments, the company has become increasingly willing to compete for the mass market sales they would in the past have conceded to rivals.
(A) they would in the past have conceded to rivals
(B) they would have conceded previously to their rivals
(C) that in the past would have been conceded previously to rivals
(D) it previously would have conceded to rivals in the past          选（E）
(E) it would in the past have conceded to rivals

为何e中的答案是it would in the past have conceded to rivals这种语态呢？

 我的理解是，从逻辑上看，并不不要是虚拟结构，而是对过去确实向他们竞争对手做出让步的一种描述。

那么，如果将e改为it in the past  conceded to rivals是否更合适？

 另外，e答案中的would表示什么意思？难道是可能的意思？那就是说concede这个动作确实没有发生？那e又成为了一种虚拟语气？

该如何解答？请教nn们

我的理解：

【过去可能会让给竞争对手的】【大市场的销售】－－有虚拟的意味，以前会让，现在不让了

意思就是，

在以前，如果没有【As tis sales of computer products have surpassed those of

measuring instruments】这件事的话，大市场销售可能就让给竞争对手了。

现在，有了【As tis sales of computer products have surpassed those of

measuring instruments】这件事，则【过去可能会让给竞争对手的】【大市场的销售】现在要compete for了。

你说的“过去确实向他们竞争对手做出让步的一种描述”

我觉的该用had done表是完成，