Fred's Fabrication has the following aggregate demand requirements and other data for the upcoming four quarters.

Quarter	Demand		Previous quarter's output	800 units
1	700		Beginning inventory	0 units
2	900		Stockout cost	$100 per unit
3	1200		Inventory holding cost	$10 per unit at end of quarter
4	600		Hiring workers	$20 per unit
			Laying off workers	$40 per unit
			Subcontracting cost	$200 per unit
			Unit cost	$100 per unit

Which of the following production plans is better: Plan A–chase demand by hiring and layoffs; Plan B–pure level strategy, or Plan C–700 level with the remainder by subcontracting (Show your explanation and calculation to earn full credit)?