Which tag is NOT valid for displaying text in HTML?

The tag is not a valid HTML tag for displaying text, which makes it the correct choice in this scenario. In HTML, headings are defined using specific tags such as

,

,

,

,

, and

, each representing different levels of headings from largest to smallest. The tag does not exist in HTML, hence it cannot be used effectively for text display.

On the other hand, the tags , , and are all valid HTML elements. The tag is used to indicate that the text it contains has strong importance, often displayed in bold. The tag signifies emphasized text, which is typically rendered in italics. The tag is used to make text bold without any additional importance or meaning beyond visual weight. Each of these tags serves a specific purpose in HTML for formatting text, whereas does not conform to HTML standards.