Refer to the exhibit.

Which switch interface configuration command would automatically
configure quality of service (QoS) for voice over IP (VoIP) within a QoS domain?

A.
switchport priority extend trust

B.
mls qos trust

C.
switchport priority extend cos 7

D.
auto qos voip cisco-phone

Explanation:
You can use the auto-QoS feature to simplify the deployment of existing QoS features. AutoQoS makes assumptions about the network design, and as a result, the switch can prioritize
different traffic flows and appropriately use the ingress and egress queues instead of using

the default QoS behavior. (The default is that QoS is disabled. The switch then offers besteffort service to each packet, regardless of the packet contents or size, and sends it from a
single queue.)
When you enable auto-QoS, it automatically classifies traffic based on the traffic type and
ingress packet label. The switch uses the resulting classification to choose the appropriate
egress queue.
When you enable auto-QoS by using the auto “qos voip cisco-phone”, the “auto qos voip
cisco-softphone”, or the “auto qos voip trust” interface configuration command, the switch
automatically generates a QoS configuration based on the traffic type and ingress packet
label and applies the appropriate commands automatically.
Reference:
http://www.cisco.com/en/US/docs/switches/lan/catalyst3750/software/release/12.2_40_se/co
nfiguration/guide/swqos.html#wp1231 112