You are designing an Active Directory implementation strategy to present to executives from your  company and from Contoso, Ltd. Which implementation strategy should you use?（）

• A、Upgrade the New York domain. Upgrade the Chicago domain. Create a pristine forest for Contoso, Ltd.
• B、Create a pristine forest. Upgrade the New York domain. Upgrade the Chicago domain. Do nothing further.
• C、Create pristine forest. Upgrade the New York domain. Upgrade the Chicago domain. Create a pristine forest for Contoso, Ltd.  
• D、Create a pristine forest. Upgrade the New York domain. Upgrade the Chicago domain. Create a new child domain for Contoso, Ltd.