Your network contains an Active Directory forest. The forest contains one domain. The domain
contains two sites and three domain controllers. The sites and domain controllers are configured as
shown in the following table.

The sites connect to each other by using a WAN link.
You have an Exchange Server 2013 organization that contains two servers in the Main Office site.
In Branch1, you plan to deploy one server to the Exchange Server 2013 organization.
You need to ensure that all of the Exchange Server services in Branch1 are available if the WAN link
fails after the planned deployment.
What should you do?

A.
Create a site link bridge, and then configure Branch1 as a hub site.

B.
Replace the domain controller in Branch1 with an RODC that runs Windows Server 2012.

C.
Replace the domain controller in Branch1 with a writable domain controller that runs a Server
Core installation of Windows Server 2008.

D.
Create an additional site link, and then configure Branch1 as a hub site.