Which of the following best describes the function of a thesis statement?

A thesis statement serves a critical role in an essay by presenting the main argument or focus in a clear and concise manner. It acts as a roadmap for both the writer and the reader, outlining the central idea that will be explored and supported throughout the body of the text. By articulating the main argument, the thesis statement helps to guide the direction of the discussion and provides a framework within which the various points will be developed. This clarity is essential for effective communication in writing, allowing readers to understand the writer's stance from the outset.

In contrast, summarizing the entire essay would not accurately reflect the function of a thesis statement, as it is not meant to encapsulate all ideas presented but rather to highlight one specific argument. Introducing a new topic does not align with the purpose of a thesis statement, which is to focus on a singular argument or perspective rather than diverting to new subjects. Similarly, while a conclusion summarizes findings, it is separate from the thesis statement, which is typically found at the beginning of the essay rather than at the end.