You are working with Certkiller that has made two corporate acquisitions. Each new company has a Cisco CallManager cluster and an associated gateway to the PSTN. The corporate WAN has been extended to each of the acquisitions and includes gatekeeper support.
Which inter-cluster trunking method will be most appropriate for this customer?

A.
H.225 trunk (gatekeeper-controlled)

B.
Inter-cluster trunk (non-gatekeeper-controlled)

C.
SIP trunk

D.
Inter-cluster trunk (gatekeeper-controlled)