You need to back up all of the group policies in a domain. The solution must minimize the size of the backup.
What should you use?

A.
the Add-WBSystemState cmdlet

B.
the Group Policy Management console

C.
the Wbadmin tool

D.
the Windows Server Backup feature

Explanation:
Reference:
http://technet.microsoft.com/en-us/library/cc770536.aspx
To back up a Group Policy object
1. In the Group Policy Management Console(GPMC) console tree, open Group Policy Objects in the forest
and domain containing the Group Policy object (GPO)to back up.
2. To back up a single GPO, right-click the GPO, andthen click Back Up. To back up all GPOs in the domain,
right-click Group Policy objects and click Back Up All.