You need to ensure that the new zone will be available only on DC5 and DC6

Your network contains an Active Directory domain named contoso.com. The domain contains six
domain controllers named DO, DC2, DC3, DC4, DC5 and DC6. Each domain controller has the DNS
Server server role installed and hosts an Active Directory-integrated zone for contoso.com.
You plan to create a new Active Directory-integrated zone named litwareinc.com that will be used
for testing.
You need to ensure that the new zone will be available only on DC5 and DC6.
What should you do first?

A.
Create an Active Directory connection object.

B.
Create an Active Directory site link.

C.
Create an application directory partition

D.
Change the zone replication scope.

Explanation:
Zone replication scope: All domain controllers in a specified application directory partition
Replicates zone data according to the replication scope of the specified application directory
partition. For a zone to be stored in the specified application directory partition, the DNS server
hosting the zone must be enlisted in the specified application directory partition. Use this scope
when you want zone data to be replicated to domain controllers in multiple domains but you do not
want the data to replicate to the entire forest.
Reference: Understanding DNS Zone Replication in Active Directory Domain Services