求助GWD1-Q21这道题啊~

That twenty-one ceramic dog figurines were discovered during the excavating of a 1,000-year-old Hohokam village in Tempe, Arizona, has nearly doubled the number of these artifacts known to exist.

A.That twenty-one ceramic dog figurines were discovered during the excavating
B.Twenty-one ceramic dog figurines discovered at the excavation
C.Discovering twenty-one ceramic dog figurines at the excavating
D.Ceramic dog figurines, twenty-one of which were discovered during excavating
E.The discovery of twenty-one ceramic dog figurines during the excavation
给的答案是选E~

那么：
A作为主语从句主谓一致是符合的吧？问题在哪里呢？
然后E就是有一点想不通就是discovery has doubled the number这个搭配make sense 么？