A company makes three produts A$,$ B$,$ and C using a CNC lathe machine$($s$)$ which is classified as a single resource pool. The resource is available for $700$ minutes per day. The contribution margins for A$,$ B$,$ and C are $$20,$ $$35,$ and $$45$ per unit respectively. The unit loads are $10,20,$ and $25$ minutes per unit.

Which product is most profitable to produce?