Fred's Fabrication Has the Following Aggregate Demand Requirements and Other

Fred's Fabrication has the following aggregate demand requirements and other data for the upcoming four quarters.
$\begin{array}{|l|l|l|l|}\hline\text { Quarter}& \text { Demand }& \text { Previous quarter's output } & 800 \text { units } \\\hline 1&700&\text { Beginning inventory } & 0 \text { units } \\\hline2&900&\text { Stockout cost } & \$ 100 \text { per unit } \\\hline3&1200 &\text { Iniventory holding cost } & \$ 10 \text { per unit at end of quarter } \\\hline4&600 &\text { Hiring workers } & \$ 20 \text { per unit } \\\hline &&\text { Laying off workers } & \$ 40 \text { per unit } \\\hline&& \text { Subcontracting cost } & \$ 200 \text { per unit } \\\hline&& \text { Unit cost } & \$ 100 \text { per unit }\\\hline\end{array}$

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?