13. freewriting is an exercise in which you a. rewrite an article in a magazine or newspaper. b. write only grammatically correct sentences. c. write whatever thoughts come to mind. d. revise and polish an essay.

C) wrote whatever thoughts come to mind.

This is because if you rewrite an article/essay, you are not saying what you want to say through the paper.
When you freewrite you must still use proper grammar but you can be a little more open with the form of speech.
When you revise or polish an essay you are just making corrections not actually writing about something or someone.

Hope this helps!