Your network contains an Active Directory domain.
The domain contains a server named Server1 that has the Remote Desktop Licensing (RD Licensing) role service installed.
On Server1, you enable the License server security group Group Policy setting.
You need to ensure that Server1 can issue Remote Desktop Services client access licenses (RDS CALs) to a server named Server3.
What should you do on Server3?

A.
From Remote Desktop Licensing Manager, reactivate the server.

B.
From Remote Desktop Session Host Configuration, modify the licensing mode.

C.
From Computer Management, modify the members of the Terminal Server Computers group.

D.
From Remote Desktop Licensing Manager, modify the connection method from the properties of the server.

Explanation:
Terminal Services License Server Security Group Configuration
When the TS Licensing role service is installed on the server, the Terminal Server Computers local group is created.
The license server will respond only to requests for TS CALs from terminal servers whose computer accounts are members of this group if the
Computer ConfigurationAdministrative TemplatesWindows ComponentsTerminal ServicesTS LicensingLicense server security group Group Policy setting has been enabled and applied to the license server.
By default, the Terminal Server Computers local group is empty.
Source: http://technet.microsoft.com/en-us/library/cc775331.aspx