Which of the following statements are correct concerning the security market line (SML) approach to determining the cost of equity for a firm? I. The SML approach considers the amount of unsystematic risk associated with a irm. Il. The SML approach can be applied to more firms than the dividend growth model can. III. The SML approach considers only future information. IV. The SML approach assumes the reward-to-risk ratio is constant. I and IlI only Il and IV only Ill and IV ony , I, and Ill only l, I, II, and IV