Factory overhead includes: a. Indirect labor but not indirect materials. b. All manufacturing costs except direct materials and direct labor. c. All manufacturing costs. d. Indirect materials but not indirect labor. 2. Costs that vary in proportion Co volume changes, but not directly arc considered. a. semivariable costs. b. factory overhead costs. c. variable costs.d. personnel costs. 3. Costs that remain the same, in total, when production levels change are: a. fixed costs, b. semivariable costs. c. direct labor costs. d. factory burden costs