The version that revises the sentence in the clearest and most grammatically correct way is C) "however, he had many other accomplishments besides that one".
The sentence "however, he was a man who accomplished many other accomplishments besides it" must be revised because using "accomplished" and "accomplishments" makes it redundant, that is to say it creates unnecessary repetition of words. Furthermore, option A) is ungrammatical, option B) is also redundant due to the use of "accomplished" and "accomplishments" and option D) is incomplete since "more" should be followed by another word. In that way, C) is the correct answer because it includes a non-redundant and gramatically correct sentence.
