Final answer:
The correct answer is Economic order quantity. It is a formula used in inventory management to calculate the optimal order quantity that minimizes total costs.
Step-by-step explanation:
The correct answer is d) Economic order quantity. The overage cost and underage cost mentioned in the question suggest that the concept being discussed is related to inventory management. The Economic Order Quantity (EOQ) is a formula used in inventory management to calculate the optimal order quantity that minimizes total costs. It takes into account factors such as ordering cost, carrying cost, and demand. Therefore, the EOQ is the most relevant concept to the given scenario.