问一个语法题

妙岛仙UID: 2101810

A huge flying reptile that died out with the dinosaurs some 65 million years ago , the duetzalcoatlus 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
(e) which is believed to be


专项训练十一 第五题

LQMMUID: 2148690

我选B，不知道对不对。it 指a huge flying reptile。