new Overload函数输出

请猜测下列程序输出：

using System;
public abstract class A
{
   public A()
   {
       Console.WriteLine('A');
   }
   public virtual void Fun()
   {
       Console.WriteLine("A.Fun()");
   }
}
public class B: A
{
   public B()
   {
       Console.WriteLine('B');
   }

   public new void Fun()
   {
       Console.WriteLine("B.Fun()");
   }

   public static void Main()
   {
       A a = new B();
       a.Fun();
   }
}