Your network includes Windows Server 2008 R2 Hyper-V failover clusters that support highly available virtual machines （VMs）.  You manage virtual machines by using Microsoft System Center Virtual Machine Manager （VMM） 2008 R2. You are planning to deploy a large number of VMs to the failover clusters. All VMs must remain available when one node of each cluster is offline. You need to determine the best placement for the new VMs among the clusters.  Which two actions should you perform？（）

• A、For each cluster， set the cluster reserve to 1
• B、In each cluster， place one host server in maintenance mode
• C、Determine the placement for each VM by using the data that is generated by running the Get-VMHostRating PowerShell cmdlet
• D、Determine the placement for each VM by using the data that is generated by running the Get-VMPerformance PowerShell cmdlet