Over five thousand years ago, archaeologists have discovered that Mesopotamian cooks were preparing chicken with coriander and tamarind, just as Egyptian cooks are still doing today.

(A) Over five thousand years ago, archaeologists have discovered that

(B) Over five thousand years ago, archaeologists had discovered that

(C) Archaeologists have discovered that, over five thousand years ago,

(D) Over five thousand years ago, as archaeologists have discovered it,

(E) Archaeologists have discovered, over five thousand years ago, that

为什么选c,不选a,

请nn帮忙。。感激不尽

a是说考古学家5000年就已经发现...
e说考古学家发现5000年...

你说选哪个?

over five thousand years ago 在 that 之前，　有歧义，　５０００年前考古学

家已经发现了．．．

但Ｄ，　不知道为什么不对，　是不是ＡＳ　用在插入语不好啊？？？