Answer: Add the Managers group to the GPO's discretionary access control list (DACL).
Deny the apply Group Policy and read permissions to the Managers group.
Step-by-step explanation:
To prevent the Group Policy object (GPO) which had been configured from applying to the members of the Managers group, the Managers group should be added to the GPO's discretionary access control list (DACL).
Likewise, the apply Group Policy can be denied and read permissions to the Managers group. This will further help in the prevention of users.