Sentence Correction

While many might not think of Joseph Moncure March to be an influential writer, his poem The Wild Party inspired beat writer William Burroughs to begin his writing career.

(A) While many might not think of Joseph Moncure March to be an influential writer
(B) While many might not think of influential writer Joseph Moncure March
(C) While many might not think of Joseph Moncure March as an influential writer
(D) While many might not think of Joseph Moncure March being an influential writer
(E) Although Joseph Moncure March was thought not to be an influential writer by many

I am quite confused why D isn't the best option, can some experts help me?

OA C