Mighty Safe Fire Alarm is currently buying 57,000 motherboards from MotherBoard, Inc., at a price of $67 per board. Mighty Safe is considering making its own boards. The costs to make the board are as follows: direct materials, $28 per unit; direct labor, $11 per unit; and variable factory overhead, $14 per unit. Fixed costs for the plant would increase by $84,000. Which option should be selected and why?

a. buy, $714,210 increase in profits

b. make, $798,000 increase in profits

c. buy, $84,000 increase in profits

d. make, $714,210 increase in profits