12. A cost that would be included in product costs under both absorption costing and variable costing is: A. supervisory salaries. B. factory rent. C. variable manufacturing costs. D. variable selling expenses. 13. The costing method that treats all fixed costs as period costs is: A. absorption costing. B. job-order costing. C. variable costing. D. process costing. 14. The opportunity cost of making a component part in a factory with excess capacity for which there is no alternative use is: A. the variable manufacturing cost of the component. B. the total manufacturing cost of the component. C. the fixed manufacturing cost of the component. D. zero. 15. Assuming that direct labor is a variable cost, the primary DIFFERENCE between the absorption and variable costing is that: A. Variable costing treats only direct materials and direct labor as product cost while absorption costing treats direct materials, direct labor, and the variable portion of manufacturing overhead as product costs. B. Variable costing treats direct materials, direct labor, the variable portion of manufacturing overhead, and an allocated portion of fixed manufacturing overhead as product costs while absorption costing treats only direct materials, direct labor, and the variable portion of manufacturing overhead as product costs. C. Variable costing treats only direct materials, direct labor, the variable portion of manufacturing overhead, and the variable portion of selling and administrative expenses as product cost while absorption costing treats direct materials, direct labor, the variable portion of manufacturing overhead, and an allocated portion of fixed manufacturing overhead as product costs. D. Variable costing treats only direct materials, direct labor, and the variable portion of manufacturing overhead as product costs while absorption costing treats direct materials, direct labor, the variable portion of manufacturing overhead, and an allocated portion of fixed manufacturing overhead as product costs