Visby Rides, a livery car company, is considering buyirg some new luxury cars. After extensive research, they come up with the above estimates of free cash flow from this project. Visby learns that a competitor is thinking of offering similar services, thus reducing Visby's sales. By how much could sales fall before the net present value (NPV) was zero, given that the cost of capital is 10%, and that cost of goods sold is 45% of revenues? A. by 20% B. by 39% C. by 31% D. by 23%