You create a Microsoft Windows Installer file for a Windows Presentation Foundation (WPF) application that requires Microsoft .NET Framework 4. You need to ensure that the installation starts only if .NET Framework 4 is already installed on the computer. What should you do?（）

• A、 Use a custom action. 
• B、 Set the MinVersion property to .NET Framework 4.
• C、 Set the Version property of Windows Installer to .NET Framework 4.
• D、 Set the Version property of the Launch Condition to .NET Framework 4.