You have an Exchange Server 2010 organization.You have a user named User1 and a user named User2. You need to ensure that User1 can add User2 to the From field when he sends e-mail messages. Messages that have User2 in the From field must display only User2 as the message sender to recipients Who receive the messages. What should you use？（）

• A、Active Directory Users and Computers
• B、Exchange Control Panel （ECP）
• C、Exchange Management Console （EMC）
• D、Microsoft Office Outlook