The corporate WAN has been extended to two newly acquired sites and it includes gatekeeper support. Each site has a Cisco CallManager and an H.323 gateway that allows connection to the PSTN. Which connection method is best for these two new customers?
A. H.225 trunk (gatekeeper-controlled)
B. intercluster trunk (non-gatekeeper controlled)
C. SIP trunk
D. intercluster trunk (gatekeeper-controlled)