Omaha Plating Corporation is considering purchasing a machine for $1,200,000. The machine is expected to generate a constant after-tax income of $80,000 per year for 15 years. The firm will use straight-line (SL) depreciation for the new machine over 10 years with no residual value. What is the payback period for the new machine? 6 years. 5 years. 15 years. 4 years. 10 years