Your virtual environment includes Windows Server 2008 R2 Hyper-V servers. You manage the environment by using Microsoft System Center Virtual Machine Manager （VMM） 2008 R2. You are planning to install an application upgrade.  Testing the production application requires access to the following three virtual machines （VMs）： a domain controller， a server that runs Microsoft SQL Server， and an IIS Web server. You need to test the application upgrade in a virtual environment that is isolated from the production network.  Which two sets of actions should your plan include？（）

• A、Pause the three VMs， and copy the .vhd files to the test environment
• B、Create a checkpoint of the three VMs， and export the checkpoint to the test environment
• C、Import the checkpoint into the test environment， and apply the application update for testing
• D、Create three VMs in the test environment， attach the existing .vhd files， and apply the application update for testing