You created a webpage containing a form for users to join your company's mailing list. Which technology should you use to validate user input with the minimum amount of bandwidth?

Utilizing client-side JavaScript for validating user input on a webpage is an effective approach to minimize bandwidth usage. Client-side validation operates within the user's browser, meaning that checks are performed before any data is sent to the server. This process allows for immediate feedback, enhancing user experience by alerting users to errors or required fields without needing to round-trip data to and from the server.

By validating input on the client side, you reduce the amount of data transmitted over the network because you can prevent invalid submissions from reaching the server. This is particularly beneficial for forms where users may make common input errors, such as incorrect formatting of email addresses or leaving required fields blank. Therefore, implementing client-side JavaScript streamlines the user interaction, making it both faster and more efficient.

Other technologies mentioned, such as server-side JavaScript, HTML validation, and CSS validation, do not offer the same level of bandwidth efficiency for input validation. Server-side JavaScript requires sending data to the server for validation, which can increase bandwidth usage. HTML validation provides basic checks but is limited in flexibility and cannot execute custom validation logic like client-side scripts. CSS validation pertains solely to styling and does not validate user input. Hence, client-side JavaScript is the preferred choice for validating