各位牛人，咨询一个语法问题

1.       A huge flying reptile that died out with the dinosaurs some 65 million years ago, the Quetzalcoatlus had a wingspan of 36 feet, believed to be the largest flying creature the world has ever seen.

(A) believed to be

(B) and that is believed to be

(C) and it is believed to have been

(D) which was, it is believed,（C）

(E) which is believed to be

我选的是A，但是答案是 C ，为什么？

谢谢

A will illogically modify the noun, a wingspan, but not the subject the Quetzalcoatlus.

B選項中的to be不對，因為這個事實是以前就被髮現暸，有一個時間段在裏麵，所以需要用have been。如果是現在最近髮現的話，就應該是to be。

E選項的which也不對，也會産生和A選項相同的糢糊指代。

那么，请教楼上一个问题，如果 B中将时态改正，and 后it and that都可以么 ？

我觉得应该可以，但是还是觉得it好一些，至于为什么，就说不清楚了，请nn指教。