Khanam Corporation, which has only one product has provided me following data concerning its most recent month of operations: The company produces the same number of units every month, although the sales in units vary from month to month. The company's variable costs per unit and total fixed costs have been constant from month to month. What is the net operating income for the month under variable costing? $18, 300 $19, 100 $4, 600 $29, 100