The following is Corporation A's contribution format income statement for last month: Sales $1,000,000 Less: variable expenses 700,000 Contribution margin 300,000 Less: fixed expenses 180,000 Operating income $120,000 The company has no beginning or ending inventories. A total of 20,000 units were produced and sold last month. What is the company's contribution marginatio? Select one a. 709 b. 150% C 30% 0.250