Which least-privilege role should be assigned to User1 so they can create groups, create access reviews for role-assignable groups, and assign Azure AD roles to groups?

The Privileged role administrator role is the correct choice because it grants the necessary permissions to manage all aspects of Azure AD roles, including assigning roles to groups, creating new groups, and creating access reviews for role-assignable groups. The Groups administrator role allows managing groups but not assigning Azure AD roles. The Authentication administrator manages authentication methods and policies, not role assignments or group creation. The Identity Governance Administrator manages access reviews and entitlements but lacks the broad permissions for creating groups and assigning all Azure AD roles that a Privileged role administrator possesses.