A car manufacturer incurs the following costs. Classify each cost as either a product or period cost. If a product cost, classify it as direct materials, direct labor, or factory overhead. If a period cost, classify it as a selling expense or a general and administrative expense. Costs Batteries for electric cars Office supplies used Wages to assembly workers Salesperson commissions Steel for cars: Depreciation on office equipment Office building insurance used up Factory building insurance used up Steering wheels used in cars Wages to paint machine operators Cost Classification Period Cost: General & Administrative Expense Period Cost: Selling Expense Product Cost: Direct Labor Product Cost: Direct Materials Product Cost: Factory Overhead