A GPO named Policy1 contains only user settings but is linked to the OU (WVDHostsOU) that contains session host computer accounts, so users' settings aren't applied at logon. What should you configure so the GPO user settings apply when users sign in to the session hosts?

Loopback processing is the correct solution because it allows user-based Group Policy Objects (GPOs) to be applied to computer objects. When a user logs on to a computer where loopback processing is enabled, the computer's GPOs are processed, and then the user's GPOs are applied based on the computer's OU, not the user's OU. This ensures that user settings defined in Policy1, which is linked to WVDHostsOU, are applied to users logging into those session hosts. FSLogix profiles are used for managing user profiles in virtual desktop environments, providing a consistent user experience and reducing logon times, but they don't address GPO application issues. Mandatory Roaming User Profiles create a read-only profile for users, but this also doesn't solve the problem of user GPOs not applying to computer objects. Restricted groups are a security feature used to control group membership, which is unrelated to GPO processing.