A manufacturer replenishes their packaging materials according to the economic order quantity model. They use $100$ cases of packaging materials per day and operate for $360$ days a year. Their current ordering policy is to order at the EOQ quantity of $720$ cases at a time. Their ordering cost per order is $$90.$ How much does it cost them to carry a case in inventory for a year?

Group of answer choices

$$50$

$$720$

$$10$

$$12\mathrm{.}5$