which component in a Cisco NAC Appliance solution does the client make a request for a Kerberos Service ticket?

When the Cisco NAS is configured for Windows Active Directory SSO to which component in a Cisco NAC Appliance solution does the client make a request for a Kerberos Service ticket?

A.
Cisco NAS

B.
Cisco NAM

C.
Microsoft Windows Active Directory Server

D.
Cisco NAA