A piece of software installed on a device requesting access to the network.

• A. Agentless NAC
• B. Persistent NAC
• C. Volatile Agent
• D. NAC Manager

Answer: (B)

End-user devices that run software to verify and enforce policies are using an endpoint agent in NAC. When that agent is installed and remains on the device to continuously participate in access decisions, it’s described as persistent. So the scenario—software installed on a device requesting network access—best fits the idea of a persistent agent providing ongoing enforcement.

Agentless NAC would rely on methods that don’t install software on the endpoint, using network signals or pre-authentication checks instead. A volatile agent would be a temporary agent that isn’t retained long-term, which doesn’t match software that stays installed. NAC Manager isn’t a standard type of NAC workflow.