Which of the following is NOT a best practice to optimize forms on mobile?

Which of the following is NOT a best practice to optimize forms on mobile?

• Exposing options instead of using a drop-down menu
• Using a real-time validation for errors in forms
• Showing labels inside form fields for convenience
• Offering users a numerical keyboard for telephone number field

Correct answer is:

• Showing labels inside form fields for convenience

Explanation: Putting labels inside fields caused problems if they disappeared when information was entered, leaving participants without guidance. Once information is entered, validate it for errors in real-time prior to submission to prevent users from having to resubmit.

Read more here: https://support.google.com/partners/answer/7336594