The owner of a number of gas stations is considering installing coffee machines in his gas stations. It will cost $290,000 to install the coffee machines, and they are expected to boost cash flows by $139,821 per year for their five-year working life. What must the cost of capital be if this investment has a profitability index of 1 ? A. 6.57% B. 13.13% C. 16.42% D. 3.28%