The correct answer is A - Virtual network peering.
According to the WGU Cybersecurity Architecture and Engineering (KFO1 / D488) Study Guide, virtual network peering enables direct communication between two or more virtual networks without the need for gateways, VPNs, or additional configurations. It allows seamless interconnectivity with minimal administrative overhead. Peered networks can communicate as if they were part of the same network, which meets the organization's request for the least administrative effort.
Other options like Virtual LANs (B) operate within the same network and don't span multiple virtual networks. Remote Desktop Protocol (C) is used for remote access, not network interconnection. Domain Name System (D) resolves names to IP addresses but does not establish communication pathways between networks.
Reference Extract from Study Guide:
"Virtual network peering provides a low-latency, high-bandwidth connection between virtual networks with minimal administrative setup. It is the recommended solution for direct communication across cloud-based virtual networks."
- WGU Cybersecurity Architecture and Engineering (KFO1 / D488), Network Architectures Module