You are developing an ASP.NET Web application. Application data is stored in a Microsoft SQL Server 2008 database. You configure a connection string named cnnContoso. The application must cache the data that is returned from the database by using this connection string. You need to ensure that the application checks the database every 10 seconds. What should you do？ （）

A.Add the following configuration to the  section of the web.config file.
B.Add the following configuration to the  section of the web.config file.
C.Add the following @ Page directive to pages that query the database.
D.Add the following @ Page directive to pages that query the database.