Your network consists of a single Active Directory forest. The sales department in your company has 600 Windows Server 2008 R2 servers. You need to recommend a solution to monitor the performance of the 600 servers. Your solution must meet the following requirements：   èGenerate alerts when the average processor usage is higher than 90 percent for 20 minutes.   èAutomatically adjust the processor monitoring threshold to allow for temporary changes in the workload.   What should you recommend？（）

• A、Install Windows System Resource Manager （WSRM） on each server.
• B、Deploy Microsoft System Center Operations Manager （OpsMgr）.
• C、Deploy Microsoft System Center Configuration Manager （SysMgr）.
• D、Configure Reliability and Performance Monitor on each server.