A business operated at 100% of capacity during its first month, with the following results: Line Item Description Amount Amount Sales (112 units) $560,000 Production costs (140 units): Direct materials $70,000 Direct labor 17,500 Variable factory overhead 31,500 Fixed factory overhead 28,000 Total production costs $147,000 Operating expenses: Variable operating expenses $5,720 Fixed operating expenses 3,270 Total operating expenses 8,990 The amount of contribution margin that would be reported on the variable costing income statement is a. $455,810 b. $559,860 c. $459,080 d. $551,010