Final answer:
the correct answer option is D. An order system with variable order quantities and a fixed order cycle is known as a periodic review system. For the survey design question, selecting whole departments at random and surveying every employee within those departments corresponds to a cluster survey design.
Step-by-step explanation:
An order system where the order quantity varies while the order cycle remains constant is known as a periodic review system. In this approach, inventory levels are checked at regular intervals or periods, and the amount ordered depends on the inventory position and future demand forecasts at that time. Unlike systems with fixed order quantities, like the two-bin system, which triggers restocking when the first bin is empty, or the reorder point system, which sets a predetermined level at which new orders are placed, the periodic review system adjusts order amounts to current needs while keeping review times unchanged.
The survey design question mentioned appears to be a cluster survey design. This approach involves dividing the population into clusters, or groups, and then randomly selecting some of these clusters to be surveyed in full. In the context provided, the 'clusters' are the four randomly chosen departments, and the survey includes all individuals within the selected clusters. This method can be a cost-effective and practical way to collect data when it is not feasible to conduct a survey across the entire population.