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. Required: a. What is the unit product cost for the month under variable costing? b. Prepare a contribution format income statement for the month using variable costing. c. Without preparing an income statement, determine the absorption costing net dperating income for the month. (Hint: Use the reconciliation method.)