Your company has an Active Directory Domain Services （AD DS） domain. You have a Windows Server 2008 R2 Hyper-V server. You manage the virtual environment by using Microsoft System Center Virtual Machine Manager （VMM） 2008 R2. You need to ensure that a user can create new virtual machines （VMs） on only a specific set of servers . The user must not be able to see or manage servers outside of that set within VMM . Which two actions should you perform？（）

• A、Create a host group. Add the host servers that the user will manage to the host group.
• B、Create a failover cluster. Join the host servers that the user will manage to the failover cluster.
• C、Using Authorization Manager， assign the user to a role with the necessary permission to manage the servers by using VMM.
• D、Using Authorization Manager， assign the user to a role with the necessary permission to manage the servers by using the VMM Self-Service Portal.