You work as the enterprise exchange administrator at TestKing.com. TestKing.com makes use of Microsoft Exchange Server messaging solution. The TestKing.com network consists of a single ActiveDirectory forest. The TestKing.com network contains the following： * Exchange Server 2007 Service Pack 1 （SP1） servers.* Exchange Server Service Pack 2 （SP2） servers. * Domain controllers running Windows Server 2003 Service Pack 1 （SP1）. You need to install Exchange Server 2010 to the TestKing.com network； however， you need to changes tothe existing servers for the installation of the Exchange 2010 servers. What should you do？（）

A. You should consider having the Exchange Server 2007 SP1 servers upgraded to Exchange Server 2007 SP2.
B. You should consider having the domain controllers upgraded to Windows Server 2003 （x64） SP2.
C. You should consider having the domain controllers to Windows Server 2008 （x64）.
D. You should consider having the Exchange Server 2003 servers upgraded to Eschange Server 2007 SP2.