Hayden Company is considering the acquisition of a machine that costs $472,000. The machine is expected to have a useful life of six years, a negligible residual value, an annual net cash flow of $93,000, and annual operating income of $79,050. What is the estimated cash payback period for the machine (round to one decimal points)? Oa. 1.2 years b. 5.1 years /c. 7.1 years Od. 6.0 years