What two types of calls can cause the Cisco Unified CallManager to send an ARQ to a gatekeeper to determine if a call should be routed?

What two types of calls can cause the Cisco Unified CallManager to send an ARQ to a gatekeeper to determine if a call should be routed? (Choose two.)

A.
calls routed to SIP gateways

B.
calls routed to H.323 gateways

C.
calls routed over an intercluster trunk

D.
calls routed to MGCP gateways

E.
calls routed to remote sites in a centralized call processing model