Your network contains an Active Directory forest. The forest contains two domains named
contoso.com and fabrikam.com. All of the DNS servers in both of the domains run Windows Server
2012 R2.
The network contains two servers named Server1 and Server2. Server1 hosts an Active Directoryintegrated zone for contoso.com. Server2 hosts an Active Directory-integrated zone for
fabrikam.com.
Server1 and Server2 connect to each other by using a WAN link. Client computers that connect to
Server1 for name resolution cannot resolve names in fabrikam.com.
You need to configure Server1 to support the resolution of names in fabrikam.com. The solution
must ensure that users in contoso.com can resolve names in fabrikam.com if the WAN link fails.
What should you do on Server1?

A.
Create a stub zone.

B.
Create a secondary zone.

C.
Add a forwarder.

D.
Create a conditional forwarder.

Explanation:
http://technet.microsoft.com/en-us/library/cc771898(v=ws.10).aspx
Stub zone doesn’t host the records themselves
Forwarder and conditional forwarders simply give instructions on where to forward DNS requests to.