You have configured a new VLAN 12 and applied it to the interface. However, you find that the computer still remains in VLAN 1. Which command will fix the issue? Refer to the following exhibit.

A. Switch(config-if)#switchport native vlan 12
B. Switch(config-if)#no switchport nonegotiate
C. Switch(config-if)#switchport mode access
D. Switch(config-if)#no spanning-tree portfast

C. The port needs to be changed from trunk mode to access mode, via the command switchport mode access. Although switchport native vlan 12 would remedy the problem, it would be an improper configuration since you are expecting tagged traffic and directing untagged traffic to VLAN 12.