Answer (D) is correct. Cost of goods sold equals beginning finished goods, plus cost of goods manufactured for a manufacturer or purchases for a retailer, minus ending finished goods. Overstated ending inventory therefore results in understated cost of goods sold, overstated net income, and overstated retained earnings in the period of the error. When these errors reverse in the following period, beginning inventory and cost of goods sold will be overstated, and net income will be understated. Retained earnings will be correct.