You have been asked to deploy Cisco Extension Mobility Cross Cluster for a distributed call processing environment. During the initial extension mobility login request, how does the visiting cluster determine if the user is a local user or a remote user?
A. by using a third-party automatic provisioning tool to verify user ID
B. by broadcasting a request to all clusters to verify the user type
C. from user IDs that are created by default when the user logs in
D. by using Extension Mobility Cross Cluster Session Initiation Protocol (SIP) trunks
E. by verifying against the local database
F. by verifying the visiting Trivial File Transfer Protocol
