You need to ensure that the client computers locate the ISATAP router

Your network contains an Active Directory domain named contoso.com. All servers run
Windows Server 2012 R2.Client computers run either Windows 7 or Windows 8.
All of the computer accounts of the client computers reside in an organizational unit (OU)
named Clients. A Group Policy object (GPO) named GPO1 is linked to the Clients OU. All of
the client computers use a DNS server named Server1.
You configure a server named Server2 as an ISATAP router. You add a host (A) record for
ISATAP to the contoso.com DNS zone.
You need to ensure that the client computers locate the ISATAP router.
What should you do?

A.
Run the Set-DnsServerGlobalQueryBlockListcmdlet on Server1,

B.
Configure the Network Options Group Policy preference of GPO1.

C.
Run the Add-DnsServerResourceRecordcmdlet on Server1.

D.
Configure the DNS Client Group Policy setting of GPO1.

Explanation:
The Set-DnsServerGlobalQueryBlockList command will change the settings of a global
query block list which you can use to ensure that client computers locate the ISATAP router.
References:
Training Guide: Installing and Configuring Windows Server 2012 R2, Chapter 4: Deploying
domain controllers, Lesson 4: Configuring IPv6/IPv4 Interoperability, p. 254-256
http://technet.microsoft.com/en-us/library/jj649942(v=wps.620).aspx
http://technet.microsoft.com/en-us/library/jj649876(v=wps.620).aspx
http://technet.microsoft.com/en-us/library/jj649874.aspx
http://technet.microsoft.com/en-us/library/jj649909.aspx