The correct answer is C. XDR (Extended Detection and Response), which is designed to provide holistic security visibility across endpoints, networks, servers, cloud workloads, and email systems. Unlike traditional endpoint-only solutions, XDR correlates data from multiple security layers to detect and respond to advanced threats.
According to the Quentin Docter – CompTIA A+ Complete Study Guide, XDR expands upon EDR by integrating telemetry from network traffic, firewalls, identity systems, and cloud platforms. This enables detection of threats that move laterally or originate outside a single host.
The Travis Everett & Andrew Hutz – All-in-One Exam Guide explains that XDR is specifically designed to detect attacks that bypass endpoint protections by analyzing network-level behavior, command-and-control traffic, and cross-system activity.
The Mike Meyers / Mark Soper Lab Manual contrasts XDR with other options: RADIUS is an authentication protocol, UAC is a local Windows privilege control, and antivirus focuses only on known malware signatures at the host level. None of those provide network-wide visibility and coordinated response.
Because the question explicitly mentions traffic outside the host and at the network level, XDR is the only technology designed to meet that requirement, making C the correct answer.
