You work as the enterprise exchange administrator at Xxx .Xxx is using Microsoft Exchange Server 2010 as their messaging solution.The Xxx contains an Exchange Server 2010 Mailbox server named XXX-EX02.What actions must you take to check when last employees logged on to XXX-EX02？（）

• A、You must configure real time block lists （RBLs）.
• B、You must use the Exchange Server User Monitor （ExMon）.
• C、You must use the Get-MailboxStatistics.
• D、You must use the administrator audit logging.