Why might you want to configure VLANs on a security appliance interface?

A.
for use in transparent firewall mode, where only VLAN interfaces are used

B.
for use in multiple context mode, where you can map only VLAN interfaces to contexts

C.
to increase the number of interfaces available to the network without adding additional physical interfaces or security appliances

D.
for use in conjunction with device-level failover to increase the reliability of your security appliance