Your network contains an Active Directory domain named adatum.com. The domain contains a 
member server named LON-DC1. LON-DC1 runs Windows Server 2012 R2 and has the DHCP 
Server server role installed.The network contains 100 client computers and 50 IP phones. The computers and the phones arefrom the same vendor. You create an IPv4 scope that contains addresses from 172.16.0.1 to 172.16.1.254.You need to ensure that the IP phones receive IP addresses in the range of 172.16.1.100 to 172.16.1.200. The solution must minimize administrative effort. 
What should you create？（）

Your network contains an Active Directory forest. The forest contains a single domain named contoso.com. The domain contains four domain controllers. The domain controllers are configured 
as shown in the following table.

You plan to deploy a new domain controller named DC5 in the contoso.com domain. You need to identify which domain controller must be online to ensure that DC5 can be promoted 
successfully to a domain controller. 
Which domain controller should you identify？（）