Hadlock Company, which has only one product, has provided the following data concerning its most recent month of operations: Selling price $91 Units in beginning inventory 0 Units produced 6,800 Units sold 6,400 Units in ending inventory 400 Variable costs per unit: Direct materials $39 Direct labor $18 Variable manufacturing overhead $ 4 Variable selling and administrative $ 8 Fixed manufacturing overhead $68,000 Fixed selling and administrative $57,600 What is the unit product cost for the month under variable costing? $61 $71 $69 $79