One advantage of topic outlines is that they provide a. topic sentences for your paragraphs b. new ideas for your outline c. internal headings for your document d. more precise ideas. i think c but i'm not sure

A topic outline usually lists the words and phrases relevant to what you’re about to craft. A topic outline also organizes your ideas in a hierarchical manner (arranging the main topics and the sub-topics), in the exact sequence that you want. It also briefly outlines what you are going to talk about. The closest answer could be letter A. It provides the topic sentences for your paragraphs   A topic sentence shows the main idea of the entire paragraph. In order to keep the text cohesive, your topic sentence should be in sync with your topic outline.