Will colleges know my scores?

<p>Say I've prepared for 2 subjects , but I want to take a third one just to see how well I will do. Do I get to decide which test scores I send or the Colleges will eventually know all my scores since my name is registered? Some people say the colleges will know all the reasoning tests scores even if you don't send them, so I don't know if the same goes for the subjests.</p>