When configuring a connection to a remote cluster, why should you configure the relevant zone with details of all peers in the duster?

When configuring a connection to a remote cluster, why should you configure the relevant zone with details of all peers in the duster?

A.
It allows a call to traverse the firewall.

B.
It allows peers within the cluster to communicate using the Cisco TelePresence Software Version TC4.0 protocol

C.
It ensures that if one cluster fails, a neighboring cluster can assume call control functionality.

D.
It ensures that a call is passed to the cluster regardless of the status of the individual peers within the cluster.