What is one definition of the central or main idea?

A. a summary of a piece of writing

B. a one-on-one or small group question-and-answer session

C. the thesis statement of original documents

D. an object created by someone with firsthand experience

The correct answer is C:the thesis statement of original documents. The thesis statement is the main or central idea of a written composition. It is the biggest, most important idea and all the other material in the composition should be connected back to this statement. The thesis is the idea that the author will try to prove. Thesis and main idea are essentially the same thing.