Which HTML5 attribute could you use with the email input to require a value?

• A. pattern
• B. placeholder
• C. maxlength
• D. required

Answer: (D)

HTML5 form validation lets you enforce input rules directly in the browser. The attribute that makes a field mandatory is required. When you attach it to an email input, the user cannot submit the form until a value is provided and that value passes the type check for an email format. This combines presence validation with the built-in format validation of the email type. Other attributes serve different purposes: pattern requires the value to match a specific regular expression but doesn’t by itself force input; placeholder is only a hint shown in the field; maxlength restricts how many characters can be entered but doesn’t compel the user to enter anything.