You are designing a migration strategy to meet the business and technical requirements. What should you do?（）

• A、Upgrade the fourthcoffee BDC to Windows Server 2003. Then upgrade the PDC to Windows Server 2003.
• B、Upgrade an existing domain controller to Windows Server 2003. Establish a two-way trust relationship with the fourthcoffee domain.  
• C、Install and configure a new Windows NT 4.0 BDC. Promote the BDC to a PDC. Then upgrade the PDC to Windows Server 2003.  
• D、Create a new Windows 2000 Server Active Directory domain. Establish a two-way trust relationship with the fourthcoffee domain. Use the Active Directory Migration Tool (ADMT) to migrate all user and computer accounts.