Which statement is true about voice VLANs?

Which statement is true about voice VLANs?

A.
The voice VLAN feature is enabled by default.

B.
When the voice VLAN feature is enabled, all untagged voice and data traffic is sent
through the voice VLAN.

C.
The default CoS value is 1 for incoming voice and data traffic.

D.
The IP phone overrides the priority of all incoming data traffic (tagged and untagged) and
sets the CoS value to 0.