8. Which of the following statements are true regarding modern portfolio theory? I. The Sharpe Optimal Portfolio is the one that maximizes returns. II. The Minimum Variance Portfolio is the one that minimizes risk III. The Efficient Frontier represents all possible investments IV. The Investment Opportunity set represents all portfolios that make sense at that level of risk. a. I and II only b. II only C. II and III only d. II, III, and IV only