What is one reason that users could see a certificate warning in their web browsers when they connect to Fireware XTM Web UI? (Select one.)
A. The Firebox or XTM device uses the default self-signed certificate.
B. The authentication server does not respond after three minutes.
C. The user has been previously added to the Blocked Sites list.
D. The user or group is not present in the Firebox User database.