Which sentence best supports the main idea in a paragraph?

• A. The sentence that introduces the topic.
• B. The sentence that gives specific evidence or details that relate to the main idea.
• C. The sentence that ends the paragraph.
• D. The sentence that describes the setting.

Answer: (B)

Think about the main idea as the heart of the paragraph. Supporting details are the facts, examples, and reasons that prove and explain that idea. The sentence that best supports the main idea is the one that adds concrete information that directly ties back to that idea—specific details, evidence, or illustrations that help you see why the main point is true.

For instance, if the main idea is that eating vegetables improves health, a supporting sentence might describe how vitamins in vegetables boost energy or how a study showed fewer illnesses among people who eat more greens. The sentence introducing the topic would set up the idea, not prove it. The ending sentence might summarize, and a sentence describing the setting would usually be about where something happened rather than about the main point. So the best support is the detail-filled sentence that explains or demonstrates the main idea.