What IP address is used for the VPN virtual cluster IP address?

What IP address is used for the VPN virtual cluster IP address?

A.
IP address within the Cisco VPN Concentrator’s private subnet address range

B.
IP address within the Cisco VPN Concentrator’s public subnet address range

C.
single IP address for the master Cisco VPN Concentrator with a separate IP address for all the
secondary Cisco VPN Concentrators

D.
single IP address that represents the master Cisco VPN Concentrator