Tortoise Coast manufactures gaming headsets. When it produces and sells 5,000 units, its costs per unit are as follows: Cost per unit Direct materials $5.70 Direct labor $2.25 Variable factory overhead $0.75 Fixed factory overhead $1.90 $0.70 Fixed selling expense Fixed administrative expense $0.40 Sales commissions $0.50 Variable administrative expense $0.55 If 4,000 units are produced, the total amount of factory overhead is: a. $12,500 b. $10,600 c. $13,250 d. $15,000