18) The principal difference between variable costing and absorption costing centers on: A) whether fixed manufacturing co sts and fixed selling and administrative costs should be included in product costs. B) whether variable manufacturing costs should be included in product costs C) whether selling and administrative costs should be included in product costs. D) whether fixed manufacturing costs should be included in product costs. Under variable costing, fixed manufacturing overhead cost is not treated as a product cost. ) A) True B) False Under absorption costing, product costs include: Fixed manufacturing overhead A) B) C) D) Variable manufacturing overhead Yes No Yes No Yes No No Yes A) Option A B) OptionB C) Option C