What tag is used for defining a section of text as an abbreviation?

The tag used for defining a section of text as an abbreviation is . This tag helps to semantically indicate that the enclosed text is an abbreviation or acronym, allowing for better accessibility and search engine optimization. Using also enables browsers and assistive technologies to provide additional context, such as displaying the full term through tooltips or screen readers. This enhances the user experience by giving clarity to readers who may not immediately understand the shortened form, thus fulfilling the purpose of improving communication through web content.

The other choices do not represent valid HTML tags for abbreviations. The tag does not exist in HTML, and neither do and . These options might seem intuitive but do not conform with standard HTML specifications, making the only accurate and functional choice for indicating abbreviations in web documents.