What is the purpose of the VLAN1 interface?

What is the purpose of the VLAN1 interface?

A.
It provides policy-based NAT for 802.1Q VLANs

B.
It provides an interface that can be used with 802.1Q VLANs in transparent mode

C.
It provides the NetScreen with a routable IP address while operating in route mode

D.
It provides an interface that can be used to remotely manage the NetScreen while
operating in transparent mode