Which of the following is correct about the C#.NET snippet given below?

namespace CuriousTabConsoleApplication
{ 
    class Baseclass
    { 
        public void fun()
        { 
            Console.WriteLine("Hi" + " ");
        } 
        public void fun(int i)
        {
            Console.Write("Hello" + " ");
        } 
    } 
    class Derived: Baseclass
    {
        public void fun()
        {
            Console.Write("Bye" + " ");
        } 
    } 
    class MyProgram
    { 
        static void Main(string[ ] args)
        { 
            Derived d; 
            d = new Derived(); 
            d.fun(); 
            d.fun(77);
        } 
    } 
}