Is it C? I choose C as the lesser of the evil since I beleive "of" is missing from the second part of the sentence but this is the nly sentence which I thought took care of the subject verb agreement. What's the answer?

My pick is C

Who became known in A is awkward.

D has a Subject Verb agreement error

E is in passive voice.

C is better because the Dependent clause is placed correctly to resolve the ambiguity about who is known for the invention and shows the contribution of LL to acceleration of the Power plant

The answer is indeed C. My query was mainly regarding the use of "research of".

I feel that the use of "OF" wrongly implies that the research is being done on these scientists rather than by them. Any suggestions?

The pioneering research of Lewis Latimer and Thomas Edison, who became known for his invention of the light bulb, accelerated the development of the first power plant, which opened in New York City in 1882.

A. of Lewis Latimer and Thomas Edison, who became known for his invention of the light bulb, (pronoun error)
B. of Lewis Latimer and Thomas Edison, known for his invention of the light bulb, (pronoun error)
C. of Thomas Edison, known for his invention of the light bulb, and Lewis Latimer (Correct)
D. of Lewis Latimer and Thomas Edison became known for his invention of the light bulb and (pronoun error)
E. that was conducted by Thomas Edison, who became known for his invention of the light bulb, and Lewis Latimer(passive voice)