A FortiGate unit operating in NAT/route mode and configured with two sub-interface on the same physical interface. Which of the following statement is correct
regarding the VLAN IDs in this scenario?

A.
The two VLAN sub-interfaces can have the same VLAN IDs only if they have IP addresses in different subnets.

B.
The two VLAN sub-interfaces must have different VLAN IDs.

C.
The two VLAN sub-interfaces can have VLAN ID only if they belong to different VDOMs.

D.
The two VLAN sub-interfaces can have the same VLAN if they are connected to different L2 IEEE 802.1Q complaint switches.