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.