Sentence correction

[NiannianX461]

8. 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,
(E) which is believed to be
Why the answer is C, not A.

[RonPurewal]

hi,
please read the forum rules before posting.

per the forum rules, we need a citation of the original source of the problem.
(i.e., the actual copyright holder of the problem--not another forum or other second-hand attribution)

also, please ask specific questions.
what didn't you like about the correct answer?
what DID you like about the answer you chose?
which particular construction(s) was/were the source of the confusion?
etc.

thanks.

[RonPurewal]

also, please title the thread correctly according to the forum rules.

per the forum rules, the title of the thread should consist of the first few words of the problem text.

since this thread runs afoul of so many of the forum rules, i'm going to lock it; please post a new thread that conforms to the rules mentioned. thanks.