What is the purpose of the native VLAN?

What is the purpose of the native VLAN?

A.
The native VLAN is used to assign the trunk’s default VLAN if a global default VLAN is not
configured.

B.
The native VLAN is only used on VoIP interfaces to allow a separate VLAN-ID for the voice
VLAN and data VLAN.

C.
The native VLAN assumes VLAN 1 when no default VLAN is configured.

D.
The native VLAN allows the interface to accept untagged packets.