A stock had annual returns of 7.63 percent, 9.28 percent, -3.11 percent, and 15.09 percent for the past four years, respectively. What is the real average rate of return for this period if inflation averaged 2.3 percent? Select one: a. 4.81% b. 5.36% c. 5.24% d. 5.02% e. 4.15%