What best describes a periodic inventory control system?

A periodic inventory control system is characterized by counting inventory at regular intervals rather than updating it continuously with each sale. This approach involves conducting physical counts of stock at specific times, such as monthly or annually, to assess inventory levels and determine the cost of goods sold. By scheduling these counts, businesses can effectively manage and evaluate their inventory without the need for real-time updates, which may require more sophisticated tracking systems.

In contrast, continuous inventory systems, which update inventory levels immediately with each sale, provide a different methodology that allows for constant real-time tracking. Options that mention updates based on sales projections or maintaining inventory for a fixed period do not align with the fundamental operation of a periodic inventory control, which is focused on scheduled counts rather than prediction or fixed intervals without assessment. Therefore, the periodic inventory system's core concept is best captured by the description of counting inventory at regular intervals.