A lift station sewage pump initially costs $20,000. Annual maintenance costs are $300. The pump salvage value is 10 percent of the initial cost in 20 years. Using an annual interest rate of 4%, the total present cost of the pump is most nearly [Hint: Treat the salvage value of the pump as a benefit (ie, negative cost)). O $15,000 O $23,200 $31,100 O $40,000