How to call a base class method even derived class object is created.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace InheritenceExample
{
    class Program
    {
        static void Main(string[] args)
        {
            b obja = new b();
            obja.Method1();
            Console.ReadLine();
        }
    }


    public class a
    {
        public virtual void Method1()
        {
            Console.WriteLine("base class method  is called.");
        }
    }

    public class b : a
    {
        public override void Method1()
        {
            base.Method1(); // calling base class method.
        }
    }

}

Result :  Base class method is called.