Inserting the "Managers" QuickLink population as the dynamic scope in the QuickLink object is a valid step when creating a custom QuickLink that should only be accessible by managers. QuickLink populations are used to define which users have access to specific QuickLinks based on criteria like role, department, or other attributes. By assigning the "Managers" population, only users who are members of that population will see and be able to launch the QuickLink.
Therefore, the correct answer is A. Yes.