Wilkerson is using both "transaction" and "duration" drivers. Number of production runs and number of shipments are transaction drivers. What assumption is being made by allocating overhead based on, for example, number of shipments? Wilkerson is using both "transaction" and "duration" drivers. Number of production runs and number of shipments are transaction drivers. What assumption is being made by allocating overhead based on, for example, number of shipments? That each shipment requires about the same amount of support That each shipment requires different amounts of support That some shipments will take longer than others That the post office will make all shipments