Consider two investors, Will Smythe and Katherine Banning, who desire to invest 100 percent of their available funds in the optimal risky portfolio. Smythe invests his money in a portfolio with an expected return of 14 percent and a standard deviation of 10 percent. Banning invests her funds in a portfolio with an expected return of 19 percent and a standard deviation of 12 percent. Which of the two investors has invested their funds in the optimal portfolio（）
A. Smythe, since his portfolio has minimized total risk.
B. Banning, since the expected return per unit of risk is higher for her investment.
C. Both, since the optimal portfolio depends on an investor’s individual utility function.
