Jamal Corporation, which produced and sold a single product, has provided the following data concerning its most recent month of operations: Selling price $ 90 Units in beginning inventory Units produced Units sold Units in ending inventory 0 3,400 3,000 400 $ Variable costs per unit: Direct materials Direct labor Variable manufacturing overhead Variable selling and administrative expense Fixed costs: Fixed manufacturing overhead Fixed selling and administrative expense $ $ 5 22 38 6 4 $54,400 $ 3,000 What is the net operating income for the month under variable costing? a. $12,200 b. $120,400) c. $5,600 d. $2,600