What should you identify?

You work as the network administrator at Domain.com. The Domain.com network consists of a single Active Directory domain named Domain.com. All servers on the Domain.com network run Windows Server 2008. Half the client computers run Windows XP Professional, and the rest run Windows Vista.
Your job function encompasses deploying sites and subnets within the Domain.com environment. You wish to verify that you have arranged your subnet objects correctly. You need to identify the subnet object that cannot be used.
What should you identify?

A.
You should not make use of 172.16.1.0

B.
You should not make use of 10.1.1.0

C.
You should not make use of 192.168.256.0

D.
You should not make use of 11.1.1.0

Explanation:
192.168.256.0 is an invalid IP address and therefore will not work as a subnet object.
Section 4, Configure Active Directory replication (10 Questions)