GWD29-7,D错在哪里呀?

Until a few centuries ago, any large bones discovered in the fields or caves of Europe, now known to be large prehistoric animals, were usually assumed to be the remains of giants and were often displayed as curiosities in castles, palaces, town halls, churches, and monasteries.

1. now known to be large prehistoric animals, were usually assumed to be
           
2. presently known as from large prehistoric animals, were usually assumed as
           
3. bones now known to be those of large prehistoric animals, were usually assumed to be
           
4. bones known at present as of large prehistoric animals, were usually assumed as those of
           
5. currently known as those of large prehistoric animals, were usually assumed to be those of

不知道D错在那里,C的bones are remails of giants 不太对吧?

多谢班主。

D错是因为有了remains就不再需要those了吗？

know as是“也称之为“，“别名”

assume as不存在。