ABC Company is considering the purchase of a new pool heater at a cost of $16,000. The new heater has an 8-year useful life with no salvage value. The new heater is expected to save $4,000 per year in cash operating costs in the first 3 years, $3,000 per year in years 4 and 5, and $1,000 per year in years 6 through 8. What is the payback period of this investment? O 4 years and 6 months O 4 years O 5 years 4 years and 4 months 4 years and 3 months