Problem No$.5.$ Fred's Fabrication has the foilowing aggregate demand requirements and other data for the upcoming four quarters. $(30$ points$)$

$\backslash$table$[[,,,],[2,700,$Beginning quarter's output,$800$ units$],[2,900,\backslash$table$[[$Beginning inventory$],[$Stockout$]],0$ units$],[3,1200,$Stockout cost,$$100$ per unit$],[4,600,$Inventory holding cost,$$10$ per unit at end of quarter$],[,,$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.