Programming in C#: Create a base class titled ReadingMaterial. Include subclasses of Online, Book and Magazine. Design your classes so that common characteristics are placed in the ReadingMaterial class. Provide the unique characteristics of the subclasses in the derived classes. Define a interface called IPrintable that has a method that returns as a string how it is available in hard copy form (i.e., printable PDF, from a publisher or from a bookstore). Include a presentation class to test this design. Additional information: This also must be in a windows form application, The form contains a combo box with 3 choices. Each one opens a different version of the form that is inherited from the base class. Please post pictures of the sample output.