In a well-structured paragraph, which detail supports the main point?

The correct choice is supporting details, as these elements directly bolster and elaborate on the main point that is being made in a well-structured paragraph. Supporting details provide evidence, examples, or explanations that clarify and reinforce the topic sentence or main idea. They create a foundation upon which the reader can understand and believe the main argument being presented. By offering specific evidence or instances, these details enhance the overall coherence of the paragraph, making the main point more convincing and relatable to the audience.

While the topic sentence introduces the primary focus, and the conclusion wraps up the discussion, it is the supporting details that truly provide the substance needed to validate the central message. The main idea encompasses the overarching concept, but without supporting details, it lacks the depth required for thorough understanding.