Barrington Corporation reported the following on their contribution format income statement: Sales (12,000 units) $175,000 Less: variable expenses 100,000 Contribution margin 75,000 Less: fixed expenses 62,500 Net operating income $ 12,500 For each additional unit of sales, net operating income will increase by: A. $17.50 B. $6.25 C. $7.50 D. $5.00 E. None of the Above