A、Create a Network Load Balancing cluster that contains the Outlook Web Access servers

B、Create a Microsoft Cluster Server cluster that contains the Outlook Web Access servers

C、Create public DNS host （A） resource records for each Outlook Web Access server. Instruct each user to connect to the server that contains his or her mailbox

D、Install Microsoft Application Center 2000 on the Outlook Web Access servers. Create a Web cluster that contains all of the Outlook Web Access servers