SlickCo, a $20$X$1$ start$-$up that uses the periodic method and weighted$-$averagecosting, makes the following merchandise purchases:$20$X$1$ Units Unit costMarch $450$ $$3\mathrm{.}00$August $650$ $$3\mathrm{.}5020$X$22.$ February $550$ $$4\mathrm{.}00$October $250$ $$5\mathrm{.}00$At the end of $20$X$1,$ there are $350$ units in ending inventory. If$,$ in $20$X$2,$ SlickCo sells$800$ units, what is the $20$X$2$ cost of goods?a$.$ $$3,100$b$.$ $$3,200$c$.$ $$4,100$d$.$ $$4,200$