Starling Co. is considering disposing of a machine with a book value of $20,000 and estimated remaining life of five years. The old machine can be sold for $5,500. A new high-speed machine can be purchased at a cost of 73,000. 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 $22,600 to $20,400 if the new machine is purchased. The five-year differential effect on profit from replacing the machine is a(n) a. decrease of $73,450 h decrease of $56,500 c. increase of $56,500 Od increase of $73,450