Hayden Company is considering the acquisition of a machine that costs $501,000. The machine is expected to have a useful life of 6 years, a negligible residual value, an annual net cash inflow of $96,000, and annual operating income of $81,600. The estimated cash payback period for the machine is (round to one decimal place) a. 5.2 years b. 1.2 years c. 6.1 years d. 7.3 years