Which tag could you use to include a footer in your HTML document?

The footer tag is specifically designed to represent the footer of a section or page in an HTML document. It is used to encapsulate information that typically appears at the bottom of a page or a section, such as copyright information, links to terms of service, contact details, or social media links. When using the footer tag, it helps improve the semantics of the document, making it clear to both users and assistive technologies that the information contained within is related to the footer of the enclosing element, whether that's a complete page or a specific section of content.

The other tags mentioned serve different purposes: the section tag is used to define sections within a document that can have their own headings, the div tag is a generic container for flow content and does not convey any specific meaning, and the nav tag is specifically for navigation links. While the div tag could technically be used to create a footer-like effect by providing a container, it would not semantically indicate the content's purpose as effectively as the footer tag. Thus, the footer tag is the most appropriate choice for including a footer in an HTML document.