Which two changes should you recommend?

Your network contains an Active Directory forest named adatum.com. All domain controllers
run Windows Server 2008 R2. The functional level of the domain and the forest is Windows
Server 2008.
You deploy a new Active Directory forest named contoso.com. All domain controllers run
Windows Server 2012 R2. The functional level of the domain and the forest is Windows
Server 2012 R2.
You establish a two-way, forest trust between the forests. Both networks contain member
servers that run either Windows Server 2012 R2, Windows Server 2012, Windows Server
2008 R2 or Windows Server 2008.
You plan to use the Active Directory Migration Tool 3.2 (ADMT 3.2) to migrate user accounts
from adatum.com to contoso.com. SID history will be used in contoso.com and passwords
will be migrated by using a Password Export Server (PES).
You need to recommend which changes must be implemented to support the planned
migration.
Which two changes should you recommend? Each correct answer presents part of the
solution.

A.
In the contoso.com forest, deploy a domain controller that runs Windows Server 2008 R2.

B.
In the adatum.com forest, upgrade the functional level of the forest and the domain.

C.
In the contoso.com forest, downgrade the functional level of the forest and the domain.

D.
In the adatum.com forest, deploy a domain controller that runs Windows Server 2012 R2.