whats the answer

The following data are for Problems 7.17 to 7.19: The correlation coefficients between several pairs of stocks are as follows: Corr (A, B) = 0.85; Corr (A, C) = 0.60; Corr (A, D) = 0.45. Each stock has an expected return of 8% and a standard deviation of 20%. Question 8 (Problem Set 7.17) If your entire portfolio is now composed of stock A and you can add some of only one stock to your portfolio, would you choose (explain your choice): (a) B (b) C (c) D (d) Need more data Question 9 (Problem Set 7.18) Would the answer to Problem 7.17 change for more risk-averse or risk-tolerant investors? Explain