You use Microsoft .NET Framework 4 to create a Windows Presentation Foundation (WPF) application. You plan to allow users to customize the background colors, foreground colors, and font style of the…

You use Microsoft .NET Framework 4 to create a Windows Presentation Foundation (WPF) application. You plan to allow users to customize the background colors, foreground colors, and font style of the application. You also plan to add a TextBlock control to the application. You write the following code fragment. (Line numbers are included for reference only.) You need to ensure that the ContextMenu control is associated with the TextBlock control. You also need to ensure that the properties that can be customized are shown hierarchically. Which code fragment should you insert at line 15?