Your company has an Active Directory Domain Services (AD DS) domain. All servers run Windows
Server 2008 R2. You activate the Key Management Service (KMS) on a server to handle volume
activation for your Windows 7 client computers. Windows 7 client computers are not being
activated. The KMS licencing status is shown as Licensed. The Windows Event Log does not contain
any corresponding activation-related events. You need to ensure that the KMS server can activate
Windows 7 client computers. What should you do?

A.
Run the slmgr.vbs /dlv command.

B.
Run the slmgr.vbs /ato command.

C.
Add a DNS SOA record pointing to the KMS server.

D.
Add a DNS SRV record pointing to the KMS server.

Explanation:
http://technet.microsoft.com/en-us/library/ff793419.aspx