What is the purpose of a topic sentence in a paragraph?

The purpose of a topic sentence in a paragraph is to introduce the main idea of that paragraph. It serves as a clear statement that encapsulates the primary focus or argument that will be developed in the following sentences. A well-crafted topic sentence guides the reader by providing a roadmap of what to expect, making the overall message of the paragraph clearer and more coherent.

While other options suggest various roles—the idea of confusing the reader, summarizing the entire essay, or including unrelated information—these do not align with the role of a topic sentence. Instead, the topic sentence should foster understanding and clarity, ensuring that the reader knows what the paragraph is going to discuss.