Your network contains an Active Directory domain named contoso.com. The DNS zone for
contoso.com is Active-Directory integrated.
The domain contains 500 client computers. There are an additional 20 computers in a workgroup.
You discover that every client computer on the network can add its record to the contoso.com zone.
You need to ensure that only the client computers in the Active Directory domain can register
records in the contoso.com zone.
What should you do?
A.
Sign the contoso.com zone by using DNSSEC.
B.
Configure the Dynamic updates settings of the contoso.com zone.
C.
Configure the Security settings of the contoso.com zone.
D.
Move the contoso.com zone to a domain controller that is configured as a DNS server.
correct
“To allow only secure dynamic updates using the Windows interface
Open DNS Manager.
In the console tree, right-click the applicable zone, and then click Properties.
On the General tab, verify that the zone type is Active Directory-integrated.
In Dynamic Updates, click secure only”
https://technet.microsoft.com/en-us/library/cc753751.aspx
B