Your network consists of one Active Directory domain. The functional level of the forest is Windows
Server 2003. All domain controllers run Windows Server 2003. The relevant portion of the network is
configured as shown in the exhibit. (Click the Exhibit button.)

The Bridge all site links option is enabled.
You need to ensure that domain controllers in the spoke sites can replicate with domain controllers
in only the hub sites. The solution must ensure that domain controllers can replicate if a server fails
in one of the hub sites.
What should you do?

A.
Lower the site link costs between the spoke sites and the hub sites.

B.
Disable the Bridge all site links option. Create site link bridges that include the site links between
each spoke site and the hub sites.

C.
Disable the Bridge all site links option. Install a writable domain controller that runs Windows
Server 2008 in each hub site.

D.
Enable the global catalog server attribute for all domain controllers in the hub sites. Upgrade all
domain controllers in the spoke sites to Windows Server 2008.

Explanation:

By default, all site links are bridged so that all the sites that are not connected by an explicit site link
can communicate directly, through a chain of intermediary site links and sites. However, if you want
to ensure that domain controllers in the spoke sites do not replicate with other spoke sites when a
server fails in one of the hub sites, you need to disable the Bridge all site links option. You need to
then create site link bridges to create the site links between each spoke site and the hub sites to
ensure that domain controllers in the spoke sites can replicate with domain controllers in the hub
sites.
Configuring site link bridges
http://technet2.microsoft.com/windowsserver/en/library/b42bb443-c5cd-4539-8dfa-
917dbddb087a1033.mspx?mfr=true