单项选择题
YouhaveanExchangeServer2010organization.UsersonthenetworkuseHTTPStoconnecttoOutlookWebApp（OWA）.TheClientAccessserverusesacertificateissuedbyaninternalcertificationauthority（CA）.Youplantodeployane-mailencryptionsolutionforallusers.Youneedtoensurethatuserscansendandreceiveencryptede-mailmessagesbyusingS/MIMEfromOWA.Whatshouldyoudo？（）
A.Issueacertificatetoeachuser
B.InstructallOWAuserstoimportarootCAcertificate
C.ModifytheauthenticationsettingsoftheOWAvirtualdirectory
D.ConfiguretheClientAccessServertouseacertificateissuedbyathird-partyCA
A.UsersonthenetworkuseHTTPStoconnecttoOutlookWebApp（OWA）.TheClientAccessserverusesacertificateissuedbyaninternalcertificationauthority（CA）.Youplantodeployane-mailencryptionsolutionforallusers.Youneedtoensurethatuserscansendandreceiveencryptede-mailmessagesbyusingS/MIMEfromOWA.Whatshouldyoudo？（）
A.Issueacertificatetoeachuser
B.InstructallOWAuserstoimportarootCAcertificate
C.ModifytheauthenticationsettingsoftheOWAvirtualdirectory
D.ConfiguretheClientAccessServertouseacertificateissuedbyathird-partyCA