adkikani
Hello Arpit
adkikani,
Thank you for the query.

Quote:
She was an educator, a builder of institutions and organizations, and a major figure in the Black church and secular feminist movements as well, so one of the best-known and most well-respected African Americans of the early twentieth century was Nannie Helen Burroughs.
Is the highlighted portion redundant, making the choice incorrect?
I do not believe there is pronoun ambiguity.
I would eliminate (A) on the basis of (other than redundancy above)
a. The main subject Nannie Helen Burroughs in passive sense is too awkward[/quote]
Yes, your reason to eliminate Choice a is correct. Usage of
as well does lead to redundancy with the usage of
and in this choice.
Quote:
Coming to (C)
As an educator, a builder of institutions and organizations, and a major figure in the Black church and secular feminist movements, Nannie Helen Burroughs was one of the best-known and most well-respected African Americans of the early twentieth century.
As an educator,
(correct usage of AS + NOUN as a ROLE/ FUNCTION )a builder of institutions and organizations,
(noun modifier -1, modifying Nannie Helen Burroughs)
and a major figure in the Black church and secular feminist movements,
(noun modifier -2, modifying Nannie Helen Burroughs, correctly
connected by parallel marker - AND)Nannie Helen Burroughs was one of the best-known
and
most well-respected African Americans of the early twentieth century. [correct usage of AND again to connect two elements (verbs) to subject][/quote]
Your analysis is almost correct. I say almost because following are the lists in the correct answer choice C:
As
an educator,
a builder of institutions and organizations (embedded list), and
a major figure in the Black church and secular feminist movements (another embedded list)
So this list features all the roles.functions of
Nannie Helen Burroughs.
Now the next list is as follows:
Nannie Helen Burroughs was
one of the best-known and
most well-respected African Americans
of the early twentieth century.So this list comprises two adjectives for
Nannie Helen Burroughs.
Hope this helps.

Thanks.
Shraddha