The correct answer is option A. "It helps a writer maintain her own voice in a piece of writing".
Explanation:
Paraphrasing is basically formulating someone else's idea using your own words, but without changing the meaning of the original idea. Paraphrasing is an effective strategy for writers since they could use the idea of someone else but maintaining their own voice in the piece of writing. This would be different if writers use a quote to state the idea instead, because the idea would be stated but with the voice of the original author.
