[求助]白勇语法

The distinctive hereditary tartans that are alleged to be worn since antiquity by members of the Highland clans were in fact designed by Scottish woolen manufacturers in the eighteenth and nineteenth centuries.
(A) that are alleged to be worn
(B) alleged to have been worn
(C) that are worn, it was alleged
(D) alleged as having been worn
(E) that are worn, allegedly

这一题选B，我想知道其他答案错的原因

请教哪位大侠帮帮我

A that be没歧义情况下应省略

C it不能指代复数名词 没有指代对象

D 结构复杂不简洁

E 句子没主语或者说 主谓在没有插入语的情况下不应分开