The following activities occur at Greenwich Corporation, a company that manufactures a variety of products. Classify each of the activities below as either a unit-level, batch-level, product-level, or organization sustaining activity. a. Various individuals manage the parts inventories. b. A clerk in the factory issues purchase orders for a job. c. The personnel department trains new production workers. d. The factory's general manager meets with other department heads such as marketing to coordinate plans. e. Direct labor workers assemble products. f. Engineers design new products. g. The materials storekeeper issues raw materials to be used in jobs. h. The maintenance department performs periodic preventive maintenance on general-use equipment