Hayden Company is considering the acquisition of a machine that costs $433,000. The machine is expected to have a useful life of 6 years, a negligible residual value, an annual net cash flow of $95,000, and annual operating income of $80,750. What is the estimated cash payback period for the machine (round to one decimal points)?

a.1.2 years

b.6.5 years

c.5.4 years

d.4.6 years