Users must be required to justify why they are visiting a social media site.

To require users to justify their access to specific types of websites, such as social media sites, theCaptive Portal (Answer D)feature is used. This feature intercepts users' web requests, redirecting them to a portal where they must authenticate or provide justification for accessing the requested site. It is particularly useful in enforcing corporate policies and ensuring that access to certain types of sites is for legitimate business purposes.

References:The use of captive portals for controlling and monitoring access to web resources is a common practice in network administration, as outlined in Versa's configuration guidelines for secure network access and user authentication protocols.