Which of the following role does the Kerberos key distribution center (KDC) play in authentication?

Q: Which of the following role does the Kerberos key distribution center (KDC) play in authentication?   

• Kerberos KDC is the initial point of contact for clients requesting access to services.
• Kerberos KDC is a standard database for retrieving user profiles and settings.   
• Kerberos KDC encrypts messages sent by the user to prevent interception.
• Kerberos KDC directly manages user credentials and permissions to access different services.