Every well-formed HTML document should include:

A well-formed HTML document must include a doctype declaration, a head section, and a body section. The doctype declaration is essential as it tells the browser which version of HTML the document is using, ensuring proper rendering. The head section typically contains metadata about the document, including the title, links to stylesheets, and scripts. This information is crucial for search engines and helps in search engine optimization (SEO). The body section is where the actual content of the webpage is placed, including text, images, and other media.

The other choices contain components that are important for specific purposes but do not fulfill the basic requirement for a well-formed document. For example, while header, nav, and footer are important for structuring a webpage, they are part of the body element and do not replace the fundamental need for a head section or the doctype. Similarly, the title and script sections are contained within the head and while necessary for function and presence of a webpage, they do not form the complete essential structure required in all well-formed HTML documents.