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.
Enable BIND secondaries

B.
Create a stub zone

C.
Disable recursion

D.
Create a secondary zone

Explanation:
http://skibbz.com/understanding-of-advance-properties-settings-in-window-server-2003-and-
2008-dns-serverbind-secondaries/
Understanding Of Advance Properties Settings In Window Server 2003 And 2008 DNS
Server (BIND Secondaries)
BIND Secondaries controls the zone transfer between different vendor DNS server. It help
verifies the type of format used zone transfer, whether it is fast or slow transfer (zone
transfer). The full mean of BIND is Berkeley Internet Name domain (BIND). BIND is a based
on UNIX operating system.

Two window servers do not required BIND. BIND is only required when transfer dns zone
between two different dns server vendors (UNIX and Microsoft Window). If you are using
only Window server for dns and zone transfer you will have to disable this option in the
window dns server. However if you want the server to perform a slow zone transfer and
uncompressed data transfer then you will have to enable BIND in the dns server.
To reiterate, BIND only provide slow dns zone transfer and data compression mechanism for
DNS server.
BIND is understood to have been introduced in window server to support UNIX.
System admin will normally disable this option if they want the data in their dns zone transfer
to between primary and secondary dns server to be transfer faster in order to improve dns
queries efficiency within their network environment
Bind is used in a DNS window server, when the needs to configured zone transfer between
window server and UNIX server or operative system.
Bind is enabled when a window server is configured as a primary dns server and a UNIX
computer is configured as a secondary dns server for zone transfer.
BIND Secondaries need to be configured to mitigate, the problem of interoperability between
the two server operating system since they are from different vendors.
Note that old version of the BIND was noted to be very slow and uses an uncompressed
zone transfer format.
However, BIND in window server 2008 and later has improved this problem. This is because
it was noted that
BIND in window server 2008 and later uses faster, compressed format during zone transfer
between primary and secondary DNS server configured in for different server operating
system (UNIX and Window server).