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.

All domain controllers are DNS servers.
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?

A.
DC1

B.
DC2

C.
DC3

D.
DC4