An anticipated purchase of equipment for $520,000, with a useful life of 8 years and no residual value, is expected to yield the following annual net incomes and net cash flows: Year 1 2345678 Net Income Net Cash Flow $60,000 $120,000 50,000 110,000 50,000 110,000 40,000 100,000 40,000 80,000 40,000 80,000 40,000 60,000 40,000 60,000 What is the cash payback period? O a. 6 years Ob.3 years Oc 4 years d. 5 years