The part of an informative essay that introduces the main idea or topic is the introduction. The introduction is the opening paragraph of the essay and it sets the stage for what the essay will be about. Typically, the introduction will grab the reader's attention, provide some background information on the topic, and end with a thesis statement that presents the main idea or argument of the essay. To find the correct answer, you can analyze the purpose and structure of an essay and identify the section that presents the main idea or topic at the beginning. In this case, the correct answer is "introduction."
