You work as an application developer at Contoso.com. You use Microsoft .NET Framework 3.5 and Microsoft ADO.NET to develop an application that will connect to the Microsoft SQL Server 2005 database. The application is used under a Least-Privilege User Account （LUA） of the  operating system. You want to configure the SQL Server 2005 connection string in the app.config file to use SQL Server Express user instances.  What should you do？（）

• A、A
• B、B
• C、C
• D、D