PB2. LO 3.1 A company manufactures and sells blades that are used in riding lawnmowers. The 18-inch blade sells for $15 and has per-unit variable costs of $4 associated with its production. The company has fixed expenses of $85,000 per month. In January, the company sold 12,000 of the 18-inch blades. A. Calculate the contribution margin per unit for the 18-inch blade. B. Calculate the contribution margin ratio of the 18-inch blade. C. Prepare a contribution margin income statement for the month of January