The management of samson manufacturing has determined that production workers have been consistently using more and more labor hours while producing the same number of units, despite new technology implementation. management suspects that lack of training on the new technology has caused productivity to decline. administrative costs are currently split equally among the product lines. which of the following is the most effective cost driver to allocate administrative costs to encourage production supervisors to increase productivity? a) keep the administrative cost allocation the same and reduce the number of employees. b) allocate administrative costs based on direct materials used in manufacturing. c) allocate administrative costs based on the total sales revenue. d) allocate administrative costs based on direct labor used in manufacturing.