On a Cisco Catalyst Switch, Which Command Is Required to Send

On a Cisco Catalyst Switch, which command is required to send CDP packets on a switch port that configures a Cisco IP phone to transmit voice traffic in 802.1Q frames, tagged with the voice VLAN ID 221?

A) Device(config-if) # switchport trunk allowed vlan 221
B) Device(config-if) # switchport vlan voice 221
C) Device(config-if) # switchport voice vlan 221
D) Device(config-if) # switchport access vlan 221