You configure Outlook Web App （OWA） to require SSL.A user named User1 reports that when she connects to OWA， she receives a Web site security certificate warning message.You need to prevent User1 from receiving the warning message when she connects to OWA. What should you do？（）

A. On User1’s computer， install the erver’s root certificate into the Trusted Root CertificatioAuthorities store.
B. On the Client Access server， install the server’s root certificate into the Trusted RooCertification Authorities store.
C. From the Exchange Management Console （EMC）， assign an Outlook Web App mailbox policy to User1.
D. From the Exchange Management Console （EMC）， open owa （Default Web Site） Properties. Configure the logon format to use the user principal name （UPN）.