You are designing a strategy for migrating domain user accounts to the new Windows Server 2003 Active Directory environment. You want to identify the minimum number of trust relationships that need to be manually created to perform this operation.  Which design should you use?（）

• A、one external trust relationship
• B、two external trust relationships
• C、six external trust relationships
• D、twelve external trust relationships
• E、one two-way cross-forest trust relationship