A virtual private network is best for employees who need to authenticate and access organizational IT resources from outside the organization. A VPN creates an encrypted tunnel over a public or external network, allowing remote users to connect securely to internal resources. A local area network is limited to a specific physical site, such as an office. A wide area network connects geographically separated locations, but it is not specifically a secure remote-access mechanism for individual users. A metropolitan area network covers a city or metropolitan region. Internal auditors reviewing remote access should evaluate VPN authentication, encryption, logging, endpoint compliance, session timeout, access rights, and monitoring.
Therefore, Option D is correct.