My Kitchen Delight $($MKD$)$ is considering a new supplier for the jars used in the production process. Assume the annual demand averages $300,000$ jars. Ordering cost is $$30$ per order. The annual holding cost per unit is $30\%$ of the unit price. The price lists for the supplier are as follows. $(3$ points$)$

$\backslash$table$[[$Units Ordered,Price Per Unit$],[1-2499,$$$2\mathrm{.}80],[2500-3499,$$$2\mathrm{.}70],[3500-4999,$$$2\mathrm{.}60],[5000$ or more,$$2\mathrm{.}50]]$

a$)$ Determine the most cost$-$effective ordering quantity.

b$)$ What is the total cost for the order quantity determined in a$).$

c$)$ Summarize the inventory policy based on your calculation results.