The management of Zesty Corporation is considering the purchase of a new machine costing $400,000. The company's desired rate of return is 10%. The present value factors for $1 at compound interest of 10% for Years 1 through 5 are 0.909, 0.826, 0.751, 0.683, and 0.621, respectively. In addition to the foregoing information, use the following data in determining the acceptability in this situation: Year Operating Income Net Cash Flow 1 $100,000 $180,000 2 40,000 120,000 3 20,000 100,000 4 10,000 90,000 5 10,000 90,000 The cash payback period for this investment is a.4 years b.2 years c.5 years d.3 years