A car manufacturer incurs the following costs. Classify each cost as either a prodfict 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 Wages to paint machine operators Cost Classification Product Cost Direct Labor Factory electricity Advertising Depreciation on factory machine Batteries for electric cars Office supplies used Wages to assembly workers Salesperson commissions Factory building insurance used up Salesperson travel costs