大全8,被修饰不清弄糊涂了

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,

(E) which is believed to be

答案选C,看了讨论贴,说A的错误在于believed to be有修饰wingspan的嫌疑.可是Quetzalcoatlus和wingspan都是单数啊,用C中的it指代不是也会有指代不清的问题吗?

完全糊涂了.请指教!! 

我也在A、C间徘徊，还是倾向于后者

如果是A的话可能在形式会出现歧义，而用C一个完整的句子就避免了这一点。

并不是题中出现了多个单数或复数名词，再用it/they就一定会歧义，这属于有效性的错误，而且如果逻辑意思清晰的话就可以排除歧义，至少C在形式上没有歧义

A的believed to be 变成修饰wingspan了

it的指代没有问题，优先指代主句主语