Which user role is responsible for adding or removing user and device groups?

The Tenant Administrator role is the correct answer as it encompasses a range of responsibilities that include managing user and device groups within a Microsoft Intune environment. This role typically has the authority to create, modify, and delete groups that can be used for organizing users and devices to apply specific policies, configurations, or assignments.

The Tenant Administrator's capabilities often allow for a broader management scope across the entire Microsoft Intune setup, making it essential for effectively managing user access and device compliance. This role is critical in ensuring that the right policies are applied to the right groups, facilitating effective administration of the IT ecosystem.

In contrast, the other roles listed do have their specific functionalities but do not primarily focus on user or device group management. A Global Administrator has overarching administrative rights across Microsoft services but is not solely focused on group management. The Custom Administrator can be assigned specific permissions depending on the needs of the organization, which may not include group management. The Service Administrator typically manages services and support but does not generally have permissions related to user or device groups.