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 all 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

Explanation:
When an interface is in Transparent mode, the NetScreen device filters packets traversing the firewall without
modifying any of the source or destination information in the IP packet header. All interfaces behave as though they are part of the same network, with the NetScreen device acting much like a Layer 2 switch or bridge. In Transparent mode, the IP addresses of interfaces are set at 0.0.0.0, making the presence of the NetScreen device invisible, or "transparent," to users. By default, ScreenOS creates one function zone, the VLAN zone, and three L2 security zones: V1-Trust, V1-Untrust, and V1-DMZ. When the NetScreen device is in Transparent mode, you use the VLAN1 interface for managing the device and terminating VPN traffic. Transparent mode is a convenient means for protecting Web servers, or any other kind of server that mainly receives traffic from untrusted sources. Using Transparent mode offers the following benefits:
No need to reconfigure the IP settings of routers or protected servers No need to create Mapped or Virtual IP addresses for incoming traffic to reach protected servers