Project X has an initial cost of $68,857, and its expected net cash inflows are $10,250 per year for 10 years. The firm has a WACC of 7 percent, and Project Xs risk would be similar to that of the firm's existing assets. What is Project Xs payback period? O a. 6.52 years O b.6.72 years c. 6.12 years d. 6.00 years e. 7.00 years