Select which groups must map to UNIX GIDs on a Samba server operating as a PDC. (Select TWO correct answers.)

While Domain Administrators are important, their group mapping is typically handled by the administrator role itself, and it's not strictly a 'must map' for basic user access like Domain Users and Guests.

The 'Domain Users' group is fundamental for all regular users in the domain to access Samba shares, requiring a corresponding UNIX GID for proper permission mapping on the underlying filesystem.

The 'Domain Guests' group needs a mapped UNIX GID to allow guest accounts to access shared resources with appropriate, often restricted, permissions on the Samba server.

Domain Controllers are machine accounts, not user groups, and do not directly map to UNIX GIDs for user access purposes in the context of Samba PDC group mappings.

Domain Operators is a specific administrative group, similar to Domain Administrators, and its mapping is not a fundamental requirement for basic Samba PDC operation in the same way as general user and guest groups.