Final answer:
The minimum planning horizon in DRP is the cumulative lead time of the critical path in a distribution system, which is key to efficient supply chain management and meeting customer demands.
Step-by-step explanation:
In the context of Distribution Requirements Planning (DRP), the minimum planning horizon is c) the cumulative lead time of the critical path in a distribution system. This involves calculating the time needed to move goods from suppliers through warehouses to the customers, ensuring that the inventory levels are adequate throughout the supply chain to meet customer demands in a timely manner.
Since the critical path represents the sequence of steps that dictate the lead time for delivery, it's essential for businesses to plan for at least the cumulative lead time to maintain efficiency and customer satisfaction.