How to Inherit method but with different return type?

Question

Given the following classes:

ClassA
{
     public ClassA DoSomethingAndReturnNewObject()
     {}    
}

ClassB : ClassA
{}

ClassC : ClassA
{}

Answer 1

I finally devised the following solution. For my case it's useful enough, but it assumes that ClassA knows about it's derivatives and is limited to those two options. Not really high-level thinking, but it works. :)

ClassA
{
    public ClassA DoSomethingAndReturnNewObject()
    {
        if (this.GetType() == typeOf(ClassB))
        {
            return new ClassB(values);
        }
        else
        {
            return new ClassC(values):
        }
    }    
}

ClassB : ClassA
{}

ClassC : ClassA
{}