What does Extensible Hypertext Markup Language (XHTML) use to describe a document's visual layout?

The correct answer is that XHTML uses CSS Stylesheets to describe a document's visual layout. XHTML is a reformulation of HTML as an XML application. While XHTML does provide the structure of a web document using elements and attributes, it relies on Cascading Style Sheets (CSS) to define the visual presentation and layout.

CSS is designed specifically to separate content from design, allowing for more flexibility and control over how HTML and XHTML content is displayed in web browsers. By utilizing CSS, developers can apply styles to elements globally or on an individual basis, resulting in consistent and efficient styling across web pages.

In contrast, while HTML serves as the foundational markup language for web content, with XHTML being a stricter variant of it, it does not handle layout directly. JavaScript is primarily a scripting language used for interactivity and dynamic behavior within web pages, rather than layout. Extensible Markup Language (XML) is a markup language for data representation and does not address visual layout concerns in web documents.