Which one of the following statements is incorrect?

Answers:	A. Contribution margin does not help much a manager who is about to take a long-term decision.
	B. Under absorption costing, the value of a unit includes all product costs.
	C. GAAP recommends the use of absorption costing for inventory costing
	D. Becasue indirect manufacturing costs are not traceable to individual products, they are treated as period costs.