You use Microsoft .NET Framework 4 to create a Windows Presentation Foundation (WPF) application.
The application uses the drag-and-drop functionality.
You need to ensure that the drag-and-drop operation is stopped when a user moves the cursor outside the boundaries of the application form.
Which enumeration member should you use?()
A. DragAction.Cancel
B. DragAction.Drop
C. DragDropEffects.None
D. DragDropEffects.All