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.

$\backslash$table$[[$Costs$,$Cost Classification$],[$Wages to assembly workers,$],[$Salesperson commissions,$],[$Steel for cars,$],[$Depreciation on office equipment,$],[$Leather for car seats,$],[$Property taxes on factory building,$],[$Factory water usage,$],[$Salesperson travel costs,$],[$Wages to paint machine operators,$],[$Advertising$,]]$