Why did the less specific overload switch to a more isolated method with the same name?

Question

I have a pretty simple code:

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

Then in the program I write:

Derived d = new Derived();
int i = 1;
d.Foo(i); //prints Derived.Foo(object)

I do not understand and cannot find on the Internet why Derived.Foo (object) is being called ? How can I make sure Derived.Foo (int) is being called ?

Answer 1

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{
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  }
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