b. a topic sentence
Each body paragraph should have a topic sentence that supports the thesis statement. In writing the body paragraphs for your essay it is very necessary to have a good topic sentence in every paragraph that maintains the thesis statement. The topic sentence of a paragraph is one of the most important because it directs and summarizes the focus of the entire paragraph. If the topic sentence of your paragraph is lousy, the rest of the paragraph would probably be as lousy as the topic sentence.