Starling Co. is considering disposing of a machine with a book value of $21,600 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 68,500. 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 $23,200 to $21,000 if the new machine is purchased. The five-year differential effect on profit from replacing the machine is an) Oa. increase of $67,600 Ob. decrease of $67,600 Oc. increase of $52,000 Od decrease of $52,000 Mighty Safe Fire Alarm is currently buying 62,000 motherboards from Motherboard, Inc., at a price of $64 per board. Mighty Safe is considering making its own boards. The costs to make the board are as follows: direct materials, $30 per unit; direct labor, $12 per unit; and variable factory overhead, $14 per unit. Fixed costs for the plant would increase by $82,000. Which option should be selected and why? Oa. buy, $414,160 increase in profits Ob. buy, $82,000 increase in profits Oc. make, $414,160 increase in profits Od. make, $496,000 increase in profits Yasmin Co. can further process Product B to produce Product C. Product B is currently selling for $31 per pound and costs $28 per pound to produce. Product C would sell for $61 per pound and would require an additional cost of $25 per pound to produce. The differential cost of producing Product C is Oa. $28 per pound Ob. $31 per pound Oc. $61 per pound Od. $25 per pound