Just-in-time (JIT) production systems Select one: O a. may lead to increased inventory obsolescence. b. have been widely used since the Great Depression of the 1930s. O c. bring together all the needed materials and parts at the precise moment they are required for each production stage, not before. O d. keep inventory levels high so deliveries to customers can be made just in time. cally e. increase the number of goods in process and save money by replacing stop-and-go production with smooth movement