The Company network administrator has entered the "auto qos voip cisco-phone" command on switch R1. What does this command do？（）
A. It disables the trust boundary feature because the switch knows a Cisco IP phone is attached.
B. The switch assigns a CoS value of 5 to incoming packets.
C. If a Cisco IP phone is attached and removed， the switch continues to trust the CoS values as long as the switch is not rebooted.
D. It turns on STP to see if a Cisco IP phone is attached.
E. If a Cisco IP phone is attached， the switch trusts the Co
F. None of the other alternatives apply.
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