Kilihea Corporation produces a single product. The company's absorption costing income statement for July follows:

Kilihea Corporation

Income Statement

For the month ended July 31 Sales (12,600 units) $579,600 Cost of goods sold 417,060 Gross margin 162,540 Selling and administrative expenses: Fixed 88,200 Variable 50,400 138,600 Net operating income $23,940

During March, the company's variable production costs were $24.10 per unit and its fixed manufacturing overhead totaled $120,700.

The contribution margin per unit during July was.

$19.10

$28.10

$17.90

$1.90