Jojen Corporation produces a single product. Last year, Jojen manufactured 33,930 units and sold 28,300 units. Production costs for the year were as follows: Direct materials Direct labor Variable manufacturing overhead Fixed manufacturing overhead $288,405 $145,899 $288,405 $542,880 Sales totaled $1,287,650 for the year, variable selling and administrative expenses totaled $164,140, and fixed selling and administrative expenses totaled $206.973. There was no beginning inventory. Assume that direct labor is a variable cost. The contribution margin per unit was: Multiple Choice $19.50 per unit Multiple Choice $19.50 per unit $24.20 per unit $13.90 per unit $18.40 per unit