What defines a supporting idea in a text?

A supporting idea in a text is one that elaborates on the main idea, providing additional information, evidence, or examples that reinforce and clarify the central concept. Supporting ideas enhance the reader's understanding by offering insights that are directly connected to the main argument or theme presented in the text. This relationship is essential as it helps to develop a comprehensive view of the topic, making the overall message more convincing and impactful.

The correct choice reflects this connection, emphasizing how supporting ideas function to bolster and expand the main idea rather than detracting or diverging from it.