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C# Brainteasers

What is displayed, and why?
using System;

 class Base
{
    public virtual void Foo(int x)
    {
        Console.WriteLine ("Base.Foo(int)");
    }
}

 class Derived : Base
{
    public override void Foo(int x)
    {
        Console.WriteLine ("Derived.Foo(int)");
    }
   
    public void Foo(object o)
    {
        Console.WriteLine ("Derived.Foo(object)");
    }
}

 class Test
{
    static void Main()
    {
        Derived d = new Derived();
        int i = 10;
        d.Foo(i);
    }
}

 Answer: Derived.Foo(object) is printed - when choosing an overload, if there are any compatible methods declared in a derived class, all signatures declared in the base class are ignored - even if they're overridden in the same derived class!
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