Your network consists of a single Active Directory domain. The domain controllers run Windows Server 2008 R2. Your company’s enterprise security policy states that the domain controllers cannot contain optical drives. You need to recommend a backup and recovery plan that restores the domain controllers in the event of a catastrophic server failure.

What should you recommend?

A.
Use Windows Server Backup to back up each domain controller to a local disk. Create a Windows Recovery Environment (Windows RE) partition on each domain controller.

B.
Use Windows Server Backup to back up each domain controller to a local disk. Use Windows Deployment Services (WDS) to deploy the Windows Recovery Environment (Windows RE).

C.
Use Windows Server Backup to back up each domain controller to a remote network share.
Create a Windows Recovery Environment (Windows RE) partition on each domain controller.

D.
Use Windows Server Backup to back up each domain controller to a remote network share.
Use Windows Deployment Services (WDS) to deploy the Windows Recovery Environment (Windows RE).

Explanation:
http://technet.microsoft.com/en-us/library/cc766048(WS.10).aspx
http://technet.microsoft.com/en-us/library/cc765966(v=WS.10).aspx

(Must Read)
http://technet.microsoft.com/en-us/magazine/2008.10.desktopfiles.aspx
Special considerations
You must be a member of the Administrators group or Backup Operators group to use Windows Server Backup.
In Windows Server 2008, the firewall has been enabled by default. If you are managing the backups of another computer using the Windows Server Backup snap-in, your connectivity to the remote computer may be affected and can be resolved by changes in the firewall rules. While working on the local computer, you are not affected.
Also, if you are a current user of the previous backup feature (Ntbackup.exe) that shipped in earlier versions of Windows, and plan to switch to the new Windows Server Backup, you might be affected by the following issues and changes:
Settings for creating backups will not be upgraded when you upgrade to Windows Server 2008. You will need to reconfigure settings.

You will need a separate, dedicated disk for running scheduled backups.

Only NTFS-formatted volumes on a locally attached disk can be backed up.

You can no longer back up to tape. (However, support of tape storage drivers is still included in Windows Server 2008.) Windows Server Backup supports backing up to external and internal disks, DVDs, and shared folders.

You cannot recover backups that you created with Ntbackup.exe by using Windows Server Backup. However, a version of Ntbackup.exe is available as a download to Windows Server 2008 for users who want to recover data from backups created using Ntbackup.exe. The downloadable version of Ntbackup.exe is only for recovering backups for older versions of Windows and cannot be used to create new backups in Windows Server 2008.

Windows Server 2008 R2 including:
The ability to backup System State as a separate job as well as the ability to do incremental System State backups.
The ability to exclude specific file types, file folders, and specific files instead of having to backup an entire volume.
The ability to backup to a volume or a network share instead of requiring a dedicated disk for backups.

Windows Recovery Technical Reference

Windows Recovery Environment (Windows RE) is an extensible recovery platform based on Windows Preinstallation Environment (Windows PE). When the computer fails to start, Windows automatically fails over into this environment, and the Startup Repair tool in Windows RE automates the diagnosis and repair of an unbootable Windows Vista installation. Furthermore, Windows RE is a starting point for various tools for manual system recovery. The primary audience of this technology includes original equipment manufacturers (OEMs), original device manufacturers (ODMs), and corporate IT professionals.

Image-based Recovery from Windows RE

In the event that the Windows installation cannot be repaired with Startup Repair or other manual repair steps, Windows RE can be used to launch an image-based recovery tool.

User-created Recovery Image

Windows Vista provides end users with the ability to create a backup image of their entire operating system. End users can do this by using the Backup tool. The system image can be stored on an external hard disk, on a hard disk partition other than those imaged, or on a DVD. To restore the computer by using this system image, users must launch the restore interface from the list of Windows RE manual tools.

Factory-created Recovery Image

To facilitate restoring a computer to its factory state, a recovery image can be placed on the Windows RE partition. This eliminates the need for a separate recovery media in most cases.
If the Windows image format is used in the manufacturing process, the same operating system image can be used for recovery as well. A computer manufacturer can develop an application by using the Imaging APIs for Windows and the Windows image to restore the operating system volume. This application can be launched from the Windows RE user interface (UI) by using customizations provided by the ODM.