Pretzel Corporation reported the following on their contribution format income statement: Sales (12,000 units) $350,000 Less: variable expenses 200,000 Contribution margin $150,000 Less: fixed expenses 125,000 Net operating income $ 25,000 If sales increase by 10%, net operating income will increase by what amount? O $-0- $15,000 O $30,000 O $1,500