What will be the output of the following C# code?

namespace ConsoleApplication4
{
    abstract class A
    {
        public int i ;
        public int j ;
        public abstract void display();
    }    
    class B: A    
    {
        public int j = 5;
        public override void display() 
        {
            this.j = 3;
            Console.WriteLine(i + "  " + j);
        }
    }    
    class Program
    {
        static void Main(string[] args)
        {
            B obj = new B();
            obj.i = 1;
            obj.display();     
            Console.ReadLine();
        }
    }
}

A. 1, 5

B. 0, 5

C. 1, 0

D. 1, 3

Answer: Option D