You have just installed a Cisco VoIP phone and it will not provision. Referring to the following exhibit, what needs to be changed?

A. CDP needs to be enabled.
B. Spanning-tree PortFast needs to be removed.
C. The interface is configured with switchport nonegotiate.
D. The interface needs to be configured as a trunk.

A. The Cisco Discovery Protocol (CDP) is required for Cisco VoIP phones. It allows the switch to learn capabilities and power requirements.