You work as an Exchange Administrator for Xxx Inc.The company has a Windows 2008 Active Directorybased network.You have recently transitioned the messaging organization to Exchange 2010 from Exchange Server 2007 SP2.You need to move the mailboxes from the old messaging organization to the new messaging organization.What cautions and prerequisites will you take when moving mailboxes？（）

• A、The Move-Mailbox cmdlets in Exchange 2007 cannot be used to move mailboxes from Exchange 2007 to Exchange 2010.
• B、The mailboxes from Exchange 2007 SP1 or earlier cannot be moved.The source mailbox server must be Exchange 2007 SP2 or later.
• C、The antivirus and anti-spam updates have to be disabled prior to moving the mailboxes.
• D、The Exchange System Manager or Active Directory Users and Computer consoles cannot be used to move mailboxes from Exchange 2003 to Exchange 2010.