What should be included in the head section of an HTML document?

The head section of an HTML document is crucial for providing important information that is not directly displayed on the webpage but is essential for the browser and search engines. Including metadata and the title in the head section serves several important purposes.

Metadata can include descriptions, keywords, and author information, which help define the content of the page for search engines and can enhance SEO (Search Engine Optimization). Furthermore, the title tag within the head section defines the title of the webpage, which appears in the browser's title bar and bookmarks, making it easier for users to identify and navigate between different pages.

Additionally, the head section can link to external stylesheets, scripts, and favicon settings, all aimed at improving user experience and interface design. This cohesive structure maximizes the webpage's functionality and effectiveness.

Other options do not fulfill the requirements of the head section, as body content is specifically meant for the body section, image files need to be referenced through the body or style attributes, and while external stylesheets are essential, they represent only one aspect of what can be included in the head section.