The correct answer is: Evidnece.
Here is a quotation from the book: "Expect to revise your thesis as you draft and revise your essay. You may write several versions of a thesis statement before you find one that works, and you may revise your thesis as you gather and organize supporting evidence, draft, and revise your essay." (page 119)
McWhorter, K. T. (2016). Successful college writing: Skills, strategies, learning styles (6th ed.). Boston: Bedford/St. Martins.