You have two Exchange Server 2010 servers that have the Client Access， Hub Transport， and Mailbox server roles installed.The servers are members of a database availability group （DAG）.You need to ensure that all users can access the Client Access server if a single server or service fails.What should you do？（）

• A、from DNS manager， create two new records for the Client Access servers.
• B、from Failover Cluster Manager， create a new service named Client Access Server and assign a new IP address.
• C、Install the Network Load Balancing feature on each server and assign a second IP address to each network adapter.
• D、Deploy a hardware load balancer.Create a DNS record for the virtual IP address and configure a Client Access server array.