You have an Exchange Server 2010 organization that contains Windows Mobile 5.0 devices. Your company plans to replace all mobile devices with Windows Mobile 6.5 devices.  You need to identify which users accessed their mailboxes by using Windows Mobile 5.0 devices in thepast month.  What should you do？（）

• A、Create a Data Collector Set.
• B、Install and run the Exchange Server User Monitor （ExMon）.
• C、Export and review the Internet Information Services （IIS） logs.
• D、Enable User Agent logging， and then review the agent logs.