Tirri Corporation has provided the following information: Cost per Unit Cost per Period Direct materials $ 6.85 Direct labor $ 3.80 Variable manufacturing overhead $ 1.35 Fixed manufacturing overhead $ 23,100 Sales commissions $ 1.30 Variable administrative expense $ 0.65 Fixed selling and administrative expense $ 7,500 If the selling price is $26.80 per unit, the contribution margin per unit sold is closest to: Multiple Choice $12.85 $7.07 $16.15 $10.18