$[5$ points$]$ Consider a retailer that sells an item with a relatively stable demand rate of $960$ units per year. The annual inventory carrying rate for the retailer is $25$ percent. Suppose that the retailer operates $50$ weeks per year.Currently, the retailer purchases this item from a local supplier at a unit cost of $$100$ and a constant delivery lead time of $4$ weeks. The retailer incurs an order cost of $$500$ per order.Characterize the optimal inventory policy for this item $($i$.$e$.,$ answer both questions of how much to order and when to order$).$What are the average annual ordering and inventory holding costs for this item implied by the policy you identified in part $($a$)?$