You use Microsoft .NET Framework 4 to create a Windows Presentation Foundation (WPF) application. You create a custom control named Wheel. You need to ensure that the Speed property of Wheel can be animated. What should you do?（）

• A、 Inherit the DependencyObject class.
• B、 Declare the Speed property as a dependency property.
• C、 Declare an animation of the Speed property from within the code-behind file.
• D、 Implement the System.Windows.Media.Animation.IAnimatable interface with the Wheel class.