A remote office uses a VPN with the HQ office to register its phones for centralized management. The office has a local SIP gateway with PRI for calling and to support SRST. On the Cisco Unified Communications Manager, a device pool is created for this site with media resources that are local to Cisco Unified Communications Manager. A SIP trunk that requires an MTP connects to the gateway. Users report voice quality issues when making and receiving calls. How do you resolve this issue?

A.	Restart the phones at remote office
B.	Restart the voice gateway and switch
C.	Enable QoS on the remote office
D.	Assign an MTP that is local to the remote office to the device pool that is used by the phones.