using System;

public class Program

{

    public static void Main()

    {

        BaseClass bClass = new BaseClass();

        bClass.Display();

        DerivedClass dClass = new DerivedClass();

        dClass.Display();

        bClass = new DerivedClass();

        bClass.Display();

        bClass = dClass;

        bClass.Display();

    }

}

​

​

public class BaseClass

{

    public  virtual void  Display()

    {

        Console.WriteLine("Base Class");

    }

}

​

​

public class DerivedClass: BaseClass

{

    public  override void Display()

    {

        Console.WriteLine("Derived Class");

    }

}