Your Network contains a single AD Site.You install 10 new Exchange Server 2010 CAS.All servers are configured to use a wildcard certificate.Users connect to their Mailboxes by using Windows Mobile 6.5 devices.All devices are configured to connect to cas.contoso.com.You need to ensure that users can connect to their Mailboxes by using mail.contoso.com. Which cmdlet should you run？（）

A. set-activesyncdeviceaccessrule
B. set-activesyncmailboxpolicy
C. set-activesyncorganizationsetting
D. set-activesyncvirtualdirectory