c. Derive the expression for optimal order quantity in EOQ model where HC is the holding cost per unit of raw material, OC is the ordering cost for each order, TD is the total yearly demand, and OQ* is the optimal order quantity. (10 points) d. ABC Ltd. is engaged in sale of footballs. It's cost per order is $400 and its carrying cost per unit per month is $0.833. The annual demand for the company's product is 20,000 units. Calculate the economic order quantity i.e., the optimal order size, total orders required during a year, total carrying cost and total ordering cost for the year. (10+4+3+3 Points)