Final answer:
Actual costs, which vary with production levels, are subject to short-run fluctuations for given jobs, typically including variable costs like labor and materials.
Step-by-step explanation:
Costs that are subject to short-run fluctuations for given jobs are A) actual costs. During the short run, firms experience fluctuations in costs as they adjust production levels to meet demand. The cost of production is dependent on the sum of each input required multiplied by its associated factor payment such as wages or material costs. Variable costs, which are costs that change with the level of output, are particularly prone to short-run fluctuations.
These costs may include direct labor and raw materials, and they adjust as the company ramps up or down its production to meet the short-term demand. Conversely, fixed costs, like rent or salaries for permanent staff, remain constant regardless of production levels in the short term.