语法求教 急111

Darwin was not the first to advance a theory of evolution; his tremendous originality lay in the fact that he proposed the idea of natural selection as the means by which evolution worked.

(A) lay in the fact that he proposed the idea

(B) lay in the fact of his proposing the idea

(C) laid in the fact of his proposing the idea

(D) laid in his proposal（E）

(E) lay in his proposal

我做的答案为d，对于为什么用现在时态但是却不用第三人称的

lays呢？

谢谢行缘