Question, Help needed!

63.When drafting the Declaration of
Sentiments that was adopted at the Seneca Falls Women’s Rights Conventions in
1848, included in it by the author, Elizabeth Cady Stanton, was a call for
female enfranchisement.

A,When drafting the Declaration of
Sentiments that was adopted at the Seneca Falls Women’s Rights Conventions in
1848, included in it by the author, Elizabeth Cady Stanton, was a call for
female enfranchisement.

B. Including a
call for female enfranchisement, a draft of the Declaration of Sentiments was
adopted at the Seneca Falls Women’s Rights Conventions in 1848 that Elizabeth
Cady Stanton wrote.

C. When the
Declaration of Sentiments drafted by Elizabeth Cady Stanton was adopted at the
Seneca Falls Women’s Rights Convention in 1848, a call for female
enfranchisement had been included in it .

D.  A call for female enfranchisement,
included in Elizabeth Cady Stanton’s draft of the Declaration of Sentiments in
1848, that was adopted by the Seneca Falls Women’s Rights Convention.

E. When
Elizabeth Cady Stanton drafted the Declaration of Sentiments that was adopted
at the Seneca Falls Women’s Rights Convention in 1848, she included in it a
call for female enfranchisement.

A: 无主句的主语

B: a draft including a call改变了原文意思

C: 过去完成时没有必要；被动时态没有必要

D: 没有谓语

E: correct，it优先指代the Declaration 

我想请问大家为什么it指代的是Declaration 而不可以是convention？

难道就不会造成指代歧异吗