You need to activate the new servers by using the KMS server

Your company has an Active Directory domain.
You have a server named KMS1 that runs Windows Server 2008 R2.
You install and configure Key Management Service (KMS) on KMS1.
You plan to deploy Windows Server 2008 R2 on 10 new servers.
You install the first two servers.
The servers fail to activate by using KMS1.

You need to activate the new servers by using the KMS server.

What should you do first?

A.
Complete the installation of the remaining eight servers.

B.
Configure Windows Management Instrumentation (WMI) exceptions in Windows Firewall on the new servers.

C.
Install Volume Activation Management Tool (VAMT) on the KMS server and configure Multiple Activation Key (MAK) Proxy Activation.

D.
Install Volume Activation Management Tool (VAMT) on the KMS server and configure Multiple Activation Key (MAK) Independent Activation.

Explanation:
Key Management Service

With KMS, IT pros can complete activations on their local network, eliminating the need for individual computers to connect to Microsoft for product activation. KMS is a lightweight service that does not require a dedicated system and can easily be co-hosted on a system that provides other services. By default, volume editions of Windows 7 and Windows Server 2008 R2 connect to a system that hosts the KMS service to request activation. No action is required from the user.

KMS requires a minimum number of computers (physical or virtual machines) in a network environment. The organization must have at least five computers to activate Windows Server 2008 R2 and at least 25 computers to activate clients that are running Windows 7. These minimums are referred to as activation thresholds.

To use KMS activation with Windows 7, the computer must have the qualifying OS license (often obtained through OEMs as part of the new PC purchase) and contain a Windows Marker in BIOS.

Source: http://technet.microsoft.com/en-us/library/ff793423.aspx