What should a user do if their access is denied after trying to log in?

When access is denied after a login attempt, the most appropriate action for the user is to contact technical support or a supervisor. This step is crucial because it allows the user to resolve the issue effectively with assistance from those who have the necessary permissions and knowledge. Technical support can investigate the reasons for the denial, whether it's due to incorrect credentials, account lockout, or system issues, and can provide guidance on how to regain access.

Additionally, contacting a supervisor may be necessary if the user is part of an organization where access levels and protocols are in place. This ensures that any sensitive access issues are handled appropriately and securely.

The other options may not provide a solution to the problem. Using a different username or changing the password without notice can lead to further complications, while simply waiting does not address the underlying issue of denied access and may cause delays in accessing vital resources.