The role of supporting details in a text is to help the reader understand the central idea.
The role of supporting details in a text is to help the reader understand the central idea and to provide information about topics related to the main topic.
The role of supporting details in a text is to provide additional information and evidence that support the main topic or central idea. They help to develop and clarify the main idea by offering specific examples, explanations, facts, statistics, or anecdotes. Supporting details give more depth and substance to the topic and help the reader better understand and appreciate the main idea being presented. Therefore, the correct answer is: to help the reader understand the central idea.