6. Given the data for three different alternatives in the table to the right, determine the best alternative using the annual cash flow analysis for a MARR of 9%. A B First cost $25,000 $20,000 $15,000 O&M Cast year 2,500 1,500 1,000 Benefit/year 9,000 10,000 7,000 Salvage value 4,000 3,000 2,000 7 Tife in years