Question 25 of 26 Which of the follow is true when investors hold well-diversified portfolios ... O A. the only risk they care about on a new investment is its own-variance risk. O B. their portfolios have eliminated all risk. O C. their portfolios are inefficient portfolios O D. the only risk they care about on a new investment is its beta risk. Reset Selection 4 Points Question 26 of 26 4 Points Which of the following assets is the best proxy for the theoretical risk-free rate? O A. The expected return on the S&P 500 Index portfolio. B. The expected return on a portfolio of AAA bonds O C. The expected future return on U.S. Treasury Bills. OD. None of the above