A business operated at 100% of capacity during its first month, with the following results: Sales (120 units) $600,000 Production costs (150 units): Direct materials $75,000 Direct labor 18,750 Variable factory overhead 33,750 Fixed factory overhead 30,000 157,500 Operating expenses: Variable operating expenses $6,040 Fixed operating expenses 3,010 9,050 The amount of contribution margin that would be reported on the variable costing income statement is a. $488,950 b. $599,850 c. $491,960 d. $590,950