GMAT Sentence Correction (SC) | Re: The invention of the cotton gin, being one of the most

Let me give it a shot.
Option D seems to be the best answer.

Option A -
"being" is redundant. Removing "being" does not alter the meaning of the sentence.
the usage of past perfect is unnecessary in the first clause -
"The invention of the cotton ginhad turned cotton cloth into an affordable commodity" - simple past tense will suffice.
"before that" - the usage of the demonstrative adjective "that" is incorrect. It must always be used with a
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