Your network contains an Active Directory forest.
All domain controllersrun Windows Server 2008 R2and 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 betweendifferent 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 BINDis
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 needsto 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).