Refer to the exhibit.
When the WAN link to headquarters fails, branch users report that their audio volume is
acceptable but they experience excessive echo when they call long-distance numbers to remote
PBX phones.
Which troubleshooting step reduces echo best?
A.
Add the command input gain 3 on voice-port 0/0/0:23.
B.
Add the command output attenuation 3 on voice-port 0/0/0:23.
C.
Apply QoS on voice-port 0/0/0:23 by adding the command service-policy output priority.
D.
Apply QoS on voice-port 0/0/0:23 by adding the command service-policy output voice.