Which of the following statements is correct? which of the following statements is correct?           a. a topic sentence is typically placed at the end of the first paragraph.   b. a topic sentence should state what you want to say about the overall topic.   c. the thesis statement belongs at the bottom of the pyramidal writing structure, while topic sentences belong at the top.   d. supporting sentences should "prop up" a topic sentence, while topic sentences should relate to the thesis statement