Which one of the following statements is correct? O a. Low standard deviation and low risk premium generally correspond to wide frequency distribution. O b. If the return on t-bills is 3 percent and the inflation rate is 2 percent and the average return on large-company stocks is 10 percent, the risk premium on large-company stocks is 8 percent. O c. In order to convince investors to accept greater volatility, you must decrease the risk premium. O d. Standard deviation is a measure of volatility. O e. The rate of return on long-term treasury bonds is normally used as the risk-free rate of return