Visitors to a company's facilities are connecting to the company's corporate network Wi-Fi and open network ports. Which of the following should the security engineer implement to prevent this unauthorized access?

A VPN (Virtual Private Network) primarily secures the data transmitted over the network by encrypting it, which is beneficial for protecting information in transit. However, it does not inherently control or restrict access to the network itself, meaning visitors could still connect to it without proper authorization.

WPA3 is a security protocol designed to enhance wireless network security and protect data transmitted over Wi-Fi. While it improves encryption and security measures for wireless communications, it does not address the issue of unauthorized devices connecting to the network, which NAC is specifically designed to manage.

HIDS (Host Intrusion Detection System) monitors and analyzes the internals of a computing system rather than the network. While it can detect and alert on suspicious activity within the system, it does not prevent unauthorized devices from connecting to the network, which is the primary concern in this scenario.