You have a Microsoft Internet Security and Accelerator （ISA） 2006 server that provides all Internet accessfor your company.  You have two Mailbox servers configured in a database availability group （DAG）， two Client Accessservers， and two Hub Transport servers.  You need to recommend changes to the environment to ensure that users can access Outlook Web App（OWA） from the Internet if any single server fails.  What should you recommend？（）

• A、Configure a Client Access server array.
• B、Deploy a second ISA server and create an ISA server array.
• C、Implement Windows Network Load Balancing for the Client Access servers.
• D、Deploy two Edge Transport servers that are configured to use EdgeSync synchronization.