A company using the periodic inventory system has the following account balances: Merchandise Inventory at the beginning of the year, $3,600; Transportation-In, $650; Purchases, $10,700; Purchase Returns and Allowances, $1,950; Purchase Discounts, $330. The cost of goods purchased is equal to a. $12,670. b. $17,230. c. $9,070. d. $8,420.