Which of the existing domain controllers must be online…

Your role of Network Administrator at ABC.com includes the management of the Active Directory forest. The
network includes servers that run Windows Server 2008 R2 and Windows Server 2012.
The forest contains three domains: a root domain named ABC.com, a child domain named US.ABC.com and
another child domain named Research.US.ABC.com. The ABC.com root domain contains two Windows Server
2012 domain controllers named ABC-DC1 and ABC-DC2. ABC-DC1 contains the forest FSMO roles. ABC-DC1
contains the forest FSMO roles. ABC-DC2 contains the domain FSMO roles for the ABC.com domain.
The US.ABC.com domain contains two Windows Server 2008 R2 domain controllers named USABC- DC1 and
US-ABC-DC2. US-ABC-DC1 contains the domain FSMO roles for the US.ABC.com domain. US-ABC-DC2 is
configured as a Global Catalog Server. The Research.US.ABC.com domain contains two Windows Server
2012 domain controllers named Res-US-ABC-DC1 and Res-US-ABC-DC2. Res-US-ABC-DC1 contains the
domain FSMO roles for the Res.US.ABC.com domain. Res-US-ABC-DC2 is configured as a Global Catalog
Server.
All domain controllers in the forest are configured as DNS Servers. You plan to install a Windows Server 2008
R2 domain controller in the Research.US.ABC.com domain.
Which of the existing domain controllers must be online in order to create the planned additional domain
controller?

A.
ABC-DC1

B.
US-ABC-DC1

C.
US-ABC-DC1 and US-ABC-DC2

D.
Res-US-ABC-DC1

E.
Res-US-ABC-DC1 and Res-US-ABC-DC2

F.
US-ABC-DC1 and Res-US-ABC-DC1