Which of the Following Statements Is True

Which of the following statements is true?

A) Calculus of variations (CV) adjusts standard deviations to compare the risk of securities with different expected returns.
B) Risk-averse investors prefer securities with high standard deviations.
C) An increase in risk will result in an increase in the standard deviation.
D) Standard deviations can be computed for stock returns, but not for bond yields.
E) If the returns from a security are normally distributed, 86% of the observations fall within one standard deviation of the expected value.