It is said in the book Tmomas Edison(1847-1931)____the world leading inventor for sixty years.(2004年辽宁)

问题描述:

It is said in the book Tmomas Edison(1847-1931)____the world leading inventor for sixty years.(2004年辽宁)
A.would be B.has been C.had been D.was
why?C在这里那里错了?

这么简单:
句型:it is said (that).是"据说..."
本应该that从句里用过去完成时态,
但还有一个细节:"in this book"这本书里,可见that从句说的是客观事实,就不用过去的相关时态.