Which of the following primarily focuses on device identity and access policies?

The primary focus on device identity and access policies aligns with Network Access Control (NAC) systems. NAC solutions are implemented to enforce policies that govern which devices can access network resources based on their identity, compliance status, and user permissions. It ensures that only authorized and compliant devices are allowed to connect to the network, thus enhancing security and reducing the risk of unauthorized access.

NAC utilizes various methods for identity verification, including authentication processes that check the identity of devices trying to connect to the network. It can enforce security policies tailored to specific devices and users, providing a granular level of access control. This ensures that devices meet certain security criteria, such as having up-to-date antivirus software or patches, before granting them access to the network.

In contrast, other options serve different primary purposes. For example, a VPN focuses on creating secure connections over the internet, a firewall controls incoming and outgoing network traffic based on security rules, and DNSSEC is designed to protect the integrity of DNS data. Thus, while all these technologies play roles in network security, NAC stands out for its specific emphasis on device identity and the enforcement of access policies.