You are designing a domain naming strategy for the new environment. Which two actions should you perform?（）

• A、Register airlines.com as a new domain name.
• B、Register manifest.airlines.com as a new domain name.  
• C、Register manifest.blueyonderairlines.com as a new domain name.
• D、Maintain the existing blueyonderairlines.com registered domain name.
• E、Use the UPN suffix of airlines.com for all new users.  
• F、Use the UPN suffix of blueyonderairlines.com for all new users.