The following costs are associated with three similar machines from which one must be purchased for use in a refinery:

Machine A MachineB Machine C

First cost $203,000 $194,000 $147,000

Maintenance costs $0 first year $0 first year $0 first year

+$10,000 gradient +$13,000 gradient +$15,000 gradient

Operating costs $8,000/year $9,000/year $10,000/year

Salvage Value $21,000 $17,500 $15,000

Useful Life in years 6 6 3

If the rate of return is 6%, which is the best alternative? Use NPWto make your decision.