Which of the following statements is correct? OA. Costs incurred in the production link in the value chain for a manufacturer are expensed when incurred. B. All links in the value chain applicable to a service company are considered period costs. OC. Product costs for a merchandiser are expensed as selling, general, and administrative expensed when the related unit is sold. OD. Product costs for a merchandiser are categorized as either direct material, direct labor, or manufacturing overhead costs. OE. Period costs are relevant for purposes of calculating Gross Profit on the Income Statement for a both a merchandiser and a manufacturer.