Sullivan Company uses the periodic inventory method. The following balances were drawn from the accounts of Sullivan Company prior to the ciosing process: $24,e00 6,400 16,e00 800 Sales revenue Beginning inventory balance Purchases Transportation-in Transportation-out Purchase discounts Ending inventory balance 1,200 400 7,200 The amount of gross margin appearing on the income statement should be: O $8.400. O $7,200. O $15,600. O $18,400.