A Cisco IP phone receives untagged data traffic from an attached PC. Which action is taken by the phone? 

Answer options:

A. It drops the traffic.
B. It allows the traffic to pass through unchanged.
C. It tags the traffic with the native VLAN.
D. It tags the traffic with the default VLAN.

B

Untagged traffic from the device attached to the Cisco IP Phone passes through the phone unchanged, regardless of the trust state of the access port on the phone. Reference: https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960/software/release/12-2_40_se/configuration/guide/scg/swvoip.pdf