Identify whether each of the following costs should be classified as product costs or period costs.

(a)		Period CostsProduct Costs		Manufacturing overhead.
(b)		Period CostsProduct Costs		Selling expenses.
(c)		Period CostsProduct Costs		Administrative expenses.
(d)		Period CostsProduct Costs		Advertising expenses.
(e)		Period CostsProduct Costs		Direct labor.
(f)		Period CostsProduct Costs		Direct materials.