Donald Enterprises produces a product with the following per-unit costs: Direct materials $15.00 Direct labor 10.00 Manufacturing overhead 20.00 Last year, Donald Enterprises produced and sold 1,000 units at a sales price of $50 each. The total selling and administrative expense was $24,200. What was the per-unit prime cost? (Note: Round your answer to two decimal places.) a.$30.00 b.$15.00 c.$25.00 d.45.00