Which of the following is a method to achieve network segmentation?

Network segmentation is the practice of dividing a network into multiple segments or subnets to enhance performance and security. The correct choice emphasizes the role of properly configured internal network firewalls in achieving this segmentation.

When internal network firewalls are properly configured, they control the traffic between different segments of the network. This allows for specific security policies to be applied to each segment, controlling access to sensitive information and systems, and effectively isolating parts of the network from potential breaches or unauthorized access. This segmentation is critical in reducing attack surfaces, as it limits lateral movement within the network in case of an attack.

Other options do not effectively achieve network segmentation on their own. VPN access, while it provides a secure connection for remote users, does not inherently divide the network for security purposes. Physical location of devices can have an impact but does not address the need for logical separation between different network segments. Employee training programs are essential for security awareness, but they do not contribute to the technical aspect of network segmentation. Therefore, the option regarding properly configured internal network firewalls stands out as the most effective strategy for implementing network segmentation.