The correct answer is D.
OBJ-3.2: Network Access Control (NAC) uses a set of protocols to define and implement a policy that describes how to secure access to network nodes whenever a device initially attempts to access the network. NAC can utilize an automatic remediation process by fixing non-compliant hosts before allowing network access. Network Access Control can control access to a network with policies, including pre-admission endpoint security policy checks and post-admission controls over where users and devices can go on a network and what they can do. In this scenario, implementing NAC can identify which machines are known and trusted Dion Training assets and provide them with access to the secure internal network. NAC could also determine unknown machines (assumed to be those of CompTIA employees) and provide them with direct internet access only by placing them onto a guest network or VLAN. While MAC filtering could be used to allow or deny access to the network, it cannot by itself control which set of network resources could be utilized from a single ethernet port. A security information and event management (SIEM) system provides real-time analysis of security alerts generated by applications and network hardware. An access control list could define what ports, protocols, or IP addresses the ethernet port could be utilized. Still, it would be unable to distinguish between a Dion Training employee’s laptop and a CompTIA employee’s laptop like a NAC implementation could.