Starling Co. is considering disposing of a machine with a book value of $22,500 and estimated remaining life of five years. The old machine can be sold for $5,300. A new high-speed machine can be purchased at a cost of 68,700. It will have a useful life of five years and no residual value. It is estimated that the annual variable manufacturing costs will be reduced from $22,900 to $19,700 if the new machine is purchased. The five-year differential effect on profit from replacing the machine is a(n) a. decrease of $47,400 b. Increase of $47,400 c. increase of $61,620 d. decrease of $61,620