Is it possible to get c# to use method overload of most specific type rather than base type?

Question

If you have a method which is overloaded with a derived type, the method called at run-time depends on the type of your variable, even if the underlying object is actually o

Answer 1

public class Processor
{
    public string Compose(BaseClass item)
    {
        return item.Compose();
    }
}

public class BaseClass
{
    public string Foo { get; set; }

    public virtual string Compose()
    {
        return Foo;
    }
}

public class DerivedClass : BaseClass
{
    public string Bar { get; set; }

    public override string Compose()
    {
        return base.Compose() + Bar;
    }
}