Mountain Manufacturing Co. has a used machine with a current disposal price of $14,000, and an estimated remaining life of 6 years. A new machine is available at a price of $95,000. The new machine has the same estimated remaining life and the same capacity as the old machine, but would reduce energy costs by $23,000 per year. Both machines would have $0 salvage value. Using a minimum required rate of 15%, the net present value of a decision to replace the old machine with the new one would be:

a. ($7,968) b. ($3,904) c. $6,032 d. $14,680