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

class sum   
{
    public int x;
    public int y;
    public  int add (int a,  int b)
    {
        x = a + b;
        y = x + b;
        return 0;
    }
}    
class Program
{
    static void Main(string[] args)
    {
        sum obj1 = new sum();
        sum obj2 = new sum();   
        int a = 2;
        obj1.add(a,  a + 1);
        obj2.add(5,  a);
        Console.WriteLine(obj1.x + "  " + obj2.y);     
        Console.ReadLine();
    }
}

A. 6, 9

B. 5, 9

C. 9, 10

D. 3, 2

Answer: Option B