28. How is the cost of goods sold calculated under the periodic method? Select an answer and submit. For keyboard navigation, use the up/down arrow keys to select an answer. By adding the cost of purchases during the period to the cost of the inventory on hand at the beginning of the period and adding this figure to the cost of the inventory on hand at the end of the period. b By adding the cost of purchases during the period to the cost of the inventory on hand at the end of the period and subtracting the inventory on hand at the beginning of the period. By carefully matching selling and administrative expenses with the sales to which they are related and then reporting these expenses in the same period the associated revenue is reported. By subtracting the cost of the inventory on hand at the ending of the period from the cost of goods available for sale