An insulated shipping container supplier is considering expanding its product line. Three materials with different insulation properties are under consideration. The following information is prepared for the economic evaluation of the best material. Determine which material should be selected based on the PW method. The MARR is 6% per year and the study period is 5 years. Assume the salvage value is negligible. Material R S Initial Investment $42,000 $54,000 $57,000 Net annual revenue $10,000 at $11,900 $13,450 EOY 1, at EOY 1, increasing by increasing by $100 per year $450 per year thereafter thereafter Useful life (years) 5 5 5