Detailed Answer
Answer (D) is correct.
Under absorption costing, all manufacturing costs, both fixed and variable, are treated as product costs. Under variable costing, only variable costs of manufacturing are inventoried as product costs. Fixed manufacturing costs are expensed as period costs. Packaging and shipping costs are not product costs under either method because they are incurred after the goods have been manufactured. Instead, they are included in selling and administrative expenses for the period.