Which of the following formulas is used by a merchandising enterprise to compute cost of goods sold when a periodic inventory system is used? Select one Oa. Beginning Merchandise Inventory+ Net Purchases of Merchandise-Ending Merchandise Inventory b. Beginning Merchandise Inventory+ Net Purchases of Merchandise c. Net Purchases of Merchandise-Ending Merchandise Inventory Od. Beginning Merchandise Inventory+ Net Purchases of Merchandise+ Ending Merchandise Inventory