Which one is True? Select one: a. The principal objective of inventory management is to maximize customer service levels by ensuring items are available at all times. b. all c. The overall objective of inventory management is to achieve satisfactory levels of customer service by having sufficient quantities while keeping inventory costs reasonable. d. A lower inventory turnover ratio indicates more efficient use of inventories. e. Retail stores typically hold three types of inventory: raw materials, work in-process, and finished goods