Select correct console output ?

class A
{
    public A()
    {
        Console.WriteLine("A Class");
    }
}
class B : A
{
    public B()
    {
        Console.WriteLine("B Class");
    }
}
class Program
{
    static void Main(string[] args)
    {
        B b = new B();
        Console.ReadLine();
    }
}