A municipality 4 years ago purchased a pump for its sewage treatment plant at exist6,000. The pump had annual operating costs of exist3, 200 and these are expected to continue. This pump is expected to continue to operate satisfactorily for 6 additional years, at which tie it may be expected to have negligible salvage value. The municipality has an opportunity to purchase a new pump for exist8, 500. The new pump is estimated to have a life of 6 years, negligible salvage value at the end of its life, and an annual operating cost of exist1, 400. If the new pump is purchased, the old pump will be sold for exist1, 600. The interest rate is 12%. With no knowledge of future replacements and a 6 year study period, what option should be selected