23. The efficient frontier of risky assets is A. the portion of the investment opportunity set that lies above the global minimum variance portfolio. B. the portion of the investment opportunity set that represents the highest standard deviations. C. the portion of the investment opportunity set that includes the portfolios with the lowest standard deviation. D. the set of portfolios that have zero standard deviation. 24, Security X has expected return of 12% and standard deviation of 18%. Security Y has expected return of 15% and standard deviation of 26%. If the two securities have a correlation coefficient of 0.7, what is their covariance? A. 0.038 B. 0.070 C. 0.018 D. 0.033 E. 0.054 25. When two risky securities that are positively correlated but not perfectly correlated are held in a portfolio, A. the portfolio standard deviation will be greater than the weighted average of the individual security standard deviations. B. the portfolio standard deviation will be less than the weighted average of the individual security standard deviations. C. the portfolio standard deviation will be equal to the weighted average of the individual security standard deviations. D. the portfolio standard deviation will always be equal to the securities' covariance