问题：

[单选]

You use Microsoft .NET Framework 4 to create a Windows Presentation Foundation (WPF) application.  
The application contains a composite user control that includes a TextBox control named txtInput.  
The user control will be hosted in a window and will have handlers for the text-changed event of txtInput.  
You need to ensure that the application meets the following requirements: 
Creates a text-changed event handler named Audit_TextChanged for the txtInput control. 
Executes Audit_TextChanged even when specific handlers mark the event as handled. 
Which code segment should you add to the constructor of the user control?（）

A . txtInput.TextChanged+=Audit_TextChanged;
B . AddHandler(TextBox.TextChangedEvent, new RoutedEventHandler(Audit_TextChanged), true);
C . EventManager.RegisterClassHandler(typeof(TextBox), TextBox.TextChangedEvent, new RoutedEventHandler(Audit_TextChanged), true);
D . EventManager.RegisterClassHandler(typeof(TextBox), TextBox.TextChangedEvent, new RoutedEventHandler (Audit_TextChanged), false)