What is the difference between a topic sentence and a thesis statement?

• A. A topic sentence explains the conclusion of the essay.
• B. A thesis is the main claim of the entire essay; a topic sentence expresses the main idea of a single paragraph.
• C. A thesis sentence expresses a paragraph's main idea.
• D. A topic sentence is the main claim of the entire essay.

Answer: (B)

Understanding what each sentence does helps you see why the statement is true. A thesis statement is the main claim of the entire essay. It states the overarching argument or purpose and guides what the whole piece will prove or discuss. A topic sentence, on the other hand, introduces the main idea of a single paragraph. It signals what that paragraph will cover and how it connects to the overall thesis, but it stays focused on one part of the argument. Because the thesis is broad and covers the whole essay, while a topic sentence is narrow and tied to one paragraph, the described relationship fits best. The other ideas confuse scope: the topic sentence does not explain the essay’s conclusion, and a thesis is not about a single paragraph’s main idea.