You have an Exchange Server 2010 organization. All users connect to their mailboxes by using Microsoft Office Outlook 2007 Service Pack 2 （SP2） andWindows 7. Your companys security administrators deploy Outlook Protection Rules. You need to recommend a client connection solution for the organization to ensure that Outlook ProtectionRules can be used. What should you recommend？（）
- AUpgrade all client computers to Outlook 2010.
- BInstruct all users to connect to Outlook Web App （OWA）.
- CInstruct all users to install the Rights Management Service （RMS） client.
- DInstruct all users to install the Secure/Multipurpose Internet Mail Extensions （S/MIME） control.