Final answer:
The best technology to ensure devices comply with antivirus software requirements under a BYOD policy is Network Access Control (NAC), as it can verify compliance before granting network access.
Step-by-step explanation:
To ensure that devices connected to the network under a Bring Your Own Device (BYOD) policy have current antivirus software, the best technology Robert's organization can deploy is B. Network Access Control (NAC). Network Access Control systems enable organizations to enforce security policies on devices seeking to access the network. They can check for certain compliance requirements, such as whether a device has updated antivirus software, before allowing network access.
Network Firewalls typically control incoming and outgoing network traffic based on an applied rule set and do not check for antivirus status on devices. Network Segmentation divides the network into smaller parts to limit access and improve performance but also does not check for antivirus software. Lastly, a Virtual Private Network (VPN) extends a private network across a public network enabling users to send and receive data across shared or public networks as if their computing devices were directly connected to the private network, which does not inherently ensure antivirus compliance either.