The correct answer is: C. cost of average stock during the period.
Inventory turnover in days is a measure of how quickly a company sells its inventory. It is calculated by dividing the cost of goods sold by the average inventory. The higher the inventory turnover ratio, the faster a company sells its inventory. This can be a good thing, as it means that the company is not holding onto inventory for too long and is not incurring storage costs. However, it can also be a sign that the company is not stocking enough inventory to meet customer demand.
The cost of average stock during the period is the total cost of all the inventory that a company has on hand during a given period, divided by the number of days in that period. This figure is used to calculate the inventory turnover ratio.
The other options are incorrect because they do not measure how quickly a company sells its inventory. Option A, inventory turnover ratio, is a measure of how many times a company sells its inventory in a given period. Option B, material consumed during the period, is a measure of how much material a company uses in a given period. Option D, none of these, is simply not an option.