Which of the following are assumptions of the simple CAPM model? I. Individual trades of investors do not affect a stock's price. II. All investors plan for one identical holding period. III. All investors analyze securities in the same way and share the same economic view of the world. IV. All investors have the same level of risk aversion. O I, II, III, and IV OI, II, and III only O I, II, and IV only O II, III, and IV only