What should you do to ensure that when a user logs off of Computer1, all of the changes made to Computer1 are discarded?

Your network contains three servers that run Windows Server 2008 R2.
The servers are configured as shown in the following table:

On Server1, you configure a virtual desktop pool named Pool1.
Pool1 contains a Windows 7 virtual machine (VM) named Computer1.
You need to ensure that when a user logs off of Computer1, all of the changes made to Computer1 are discarded.

What should you do?

A.
On Server2, enable shadow copies.

B.
On Server2, take a snapshot of Computer1 and rename the snapshot RDV_Rollback.

C.
From the properties of Pool1 on Server1, modify the Automatically save virtual machines setting.

D.
From the Remote Desktop Session Host Configuration console on Server1, modify the Delete temporary folders on exit setting.

Explanation:
To enable rollback on a virtual machine

1. Log on to RD Virtualization Host using an Administrator account.
2. Open Hyper-V Manager. To open Hyper-V Manager, click Start, point to Administrative Tools, and then click Hyper-V Manager.
3. Under Virtual Machines, right-click the virtual machine to enable rollback, and then click Snapshot.
4. Under Snapshots, right-click the snapshot of the virtual machine, and then click Rename.
5. Type RDV_Rollback and then press ENTER.
6. Close Hyper-V Manager.
7. Repeat these steps for each virtual machine.

Source: http://technet.microsoft.com/en-us/library/ff710411(WS.10).aspx