118. Art museums do not usually think of their collections as capital or consider the interest income that would be generated if a portion of the capital would have been invested in another form.

(A) be generated if a portion of the capital would have been

(B) have been generated if a portion of the capital would have been

(C) be generated if a portion of the capital were

(D) be generated if a portion of the capital was（C）

(E) be generated if a portion of the capital had been

答案是C，不明白为什么用复数“were”，而不用单数形式？

大家帮忙看看！谢谢！

这里用的是虚拟语气。

例如：If I were you, I will marry her.