Your network includes Windows Server 2008 R2 Hyper-V servers. Each Hyper-V server runs multiple virtual machines （VMs）. You need to detect performance issues and generate an alert when Hyper-V server load exceeds specific thresholds.    Which tool should you use？（）

• A、Microsoft System Center Capacity Planner 2007
• B、Microsoft System Center Operations Manager 2007 R2
• C、Microsoft System Center Configuration Manager 2007 R2
• D、Microsoft System Center Virtual Machine Manager 2008 R2