A web developer need to ensure that a message appears if the user’s browser does...

To ensure that a message appears if the user’s browser does not support the audio files on a web page, the developer should use the

Correct Usage:

Fallback Content: Place the message as fallback content inside the

Example:

No mpeg support.

Explanation of Options:

Option A: Incorrect. The alt attribute is not valid for the element.

Option B: Incorrect. The alt attribute is not valid for the

Option C: Incorrect. The alt attribute is used incorrectly in the

Option D: Correct. The message "No mpeg support." is placed correctly as fallback content inside the

References:

W3C HTML5 Specification - The audio element

MDN Web Docs -

Using the fallback content inside the