there is a 5th option of 15 years

Also what would the rate of return be on the initial investment?

Omaha Plating Corporation is considering purchasing a machine for $2,200,000. The machine is expected to generate a constant after-tax income of $70,000 per year for 11 years. The firm will use straight-ine (SL) depreciation for the new machine over 8 years with no residual value. What is the payback period for the new machine? Multiple Choice 4 years. 5 years 6 years 10 years