Your network contains an Active Directory forest. All domain controllers run Windows Server 2008 R2 and are configured as DNS servers. You have an Active Directory-integrated zone for contoso.com.
You have a UNIX-based DNS server.
You need to configure your Windows Server 2008 R2 environment to allow zone transfers of the contoso.com zone to the UNIX-based DNS server.
What should you do in the DNS Manager console?

A.
Disable recursion.

B.
Create a stub zone.

C.
Create a secondary zone.

D.
Enable BIND secondaries.