You are a network technician of your company. You are reported that users are occupying most bandwidth to share file applications across the T1, this results in poor voice quality. How to solve this problem?

A.
Configure traffic shaping to reduce the bandwidth available to the file sharing application.

B.
Upgrade switches to provide higher bandwidth ports for workstations and IP phones.

C.
Configure a separate VLAN for the IP phones.

D.
Install a content caching proxy at the branch to reduce inbound WAN traffic.