You create a Microsoft ASP.NET application by using the Microsoft .NET Framework version 3.5.  The application uses Session objects. You are modifying the application to run on a Web farm. You need to ensure that the application can access the Session objects from all the servers in the Web farm. You also need to ensure that when any server in the Web farm restarts or stops responding， the Session objects are not lost. What should you do？（）

• A、A
• B、B
• C、C
• D、D