GE has delivered returns 9%, 3%, -8.5%, and -5% in years 2016 thru 2019, respectively. What is the stock's volatility and variability? a. Volatility -0.6%, Variability - 7.9% b. Volatility - 0.4%, Variability = 6.5% c. Volatility -6.5%, Variability - 0.4% d. Volatility - 7.9%, Variability - 0.6%