请教大全23?

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

那位NN帮看一下,A和C,为什么不选A呢?

谢谢!

谢谢NN. 绕过来拉.

顶起这张贴....

那么....不知道用to have been是根据什么？