Your company has a single Active Directory domain named contoso.com.
All servers in the domain run Windows Server 2008 R2.
The DNS Server server role is installed on two domain controllers named DC1 and DC2.
Both DNS servers host Active Directory-integrated zones that are configured to allow the most secure updates only.
DC1 has Key Management Service (KMS) installed and activated.
You discover that the service locator records from the contoso.com zone hosted on DC1 and DC2 are missing.

You need to force registration of the KMS service locator records in the contoso.com zone.

What should you do?

A.
Configure the contoso.com zone to accept non-secure updates.

B.
On DC1 at the command prompt, run the slmgr.vbs �rearm script.

C.
On DC1 at the command prompt, run the net stop slsvc command, and then run the net start slsvc command.

D.
On DC2 at the command prompt, run the net stop netlogon command, and then run the net start netlogon command.

Explanation:
A KMS host will automatically update its SRV entries if the software licensing service (slsvc.exe) detects that the computer name or TCP port has changed during service startup. It will also update them once each day, in order to ensure that they are not automatically removed (scavenged) by the DNS system.

Source: http://download.microsoft.com/download/c/3/8/c3815ed7-aee7-4435-802b-8e855d549154/VolumeActivation2.0Step-By-StepGuide.doc