A server administrator wants to increase the availability of a web server without implementing a cluster. Which of the following would accomplish this task?

Round robin DNS distributes connections across multiple addresses but provides no automatic failover - clients may still be directed to a downed server until the DNS TTL expires.

An active/active service configuration is a clustering model where both nodes simultaneously handle traffic, which contradicts the requirement of not implementing a cluster.

An active/passive service configuration is also a clustering model where one node is a warm standby, which is a form of clustering and violates the stated constraint.

Windows Server Network Load Balancing allows multiple servers to share a single virtual IP address, distributing incoming requests across all active nodes. If one server becomes unavailable, the remaining servers continue responding to that shared IP, providing high availability without the complexity of a Windows Server Failover Cluster.