How do you denote a comment in HTML?

The correct way to denote a comment in HTML is to use the syntax that begins with <!-- and ends with -->. This allows developers to insert notes or annotations in the code that are not displayed in the browser when the page is rendered. Using this syntax helps maintain clarity in the code by allowing explanations, reminders, or any other non-visible information without affecting the actual output of the web page.

The other options do not follow the correct formatting for HTML comments. The second choice uses angle brackets in a way that suggests it is an HTML element, which is incorrect for comments. The third choice suggests an extended version of the comment format, but additional hyphens are not valid in HTML comments. The fourth option uses hashtags and angle brackets, which does not match any HTML comment syntax. Understanding this marking is essential for writing clean and maintainable HTML code.