Which of the following needs to be configured when communicating over multiple VLANs and only...

The correct answer is D. SVI. When traffic must move between multiple VLANs, some Layer 3 function has to exist so each VLAN can have a gateway. A Switched Virtual Interface (SVI) provides a logical Layer 3 interface for a VLAN and is commonly used to support inter-VLAN communication. In exam wording, when the question points to communication across multiple VLANs, the important idea is that each VLAN needs a Layer 3 presence.

The other answer choices do not fit this requirement. Static routing is used to define network paths, but it does not by itself create the VLAN gateway interfaces needed for inter-VLAN traffic. NAT translates addresses, usually for internet access, not for switching between local VLANs. Full duplex is a link operation mode and has nothing to do with routing traffic between VLANs.

The phrase “communicating over multiple VLANs” is the key clue. VLANs are separate broadcast domains, so devices in different VLANs cannot communicate without Layer 3 intervention. Among the choices given, SVI is the only answer that provides that Layer 3 function in a switched environment. That is why D is the best answer.