Dapple Company incurred the following costs while producing 600 units: direct materials, $8 per unit; direct labor, $20 per unit, variable manufacturing overhead, $11 per unit; total fixed manufacturing overhead costs, $13,200; variable selling and administrative costs, \$9 per unit; total fixed selling and administrative costs, $8,400. There are no beginning inventories. What is the unit product cost using variable costing? A. $39 per unit B. $48 per unit C. $84 per unit D. \$61 per unit