Your network contains one Exchange Server 2010 Client Access server named Server1.You have a user named User1.You need to limit the size of the attachments that User1 can download by using Exchange ActiveSync.The solution must not affect other users.
What should you do first？（）

A.Modify the internal URL for the Microsoft-Server-ActiveSync virtual directory.
B.Modify the external URL for the Microsoft-Server-ActiveSync virtual directory.
C.Enable Anonymous Authentication for the Microsoft-Server-ActiveSync virtual directory.
D.Enable Windows Integrated Authentication for the Microsoft-Server-ActiveSync virtual directory.

A.Modify User1 Mailbox properties
B.Create a New ActiveSync Mailbox Policy
C.Create a New Exchange ActiveSync Mailbox policy
D.Modify properties of Default Exchange ActiveSync Mailbox policy

A.Exchange Control Panel （ECP）
B.Exchange Management Console （EMC）
C.Microsoft Office Outlook
D.Public Folder Management Console