What is the optimal order quantity while using a fixed$-$order$-$quantity $($EOQ$)$ inventory model if annual demand for a product is $5,000$ units, the fixed order cost is $$10,$ purchase price per unit is $$5,$ and the annual carrying cost is $$0\mathrm{.}50$ per unit? Question $1$Answer a$.141\mathrm{.}42$ units b$.5,000$ units c$.200,000$ units d$.$ None of these e$.447\mathrm{.}21$ units