Which costs vary with the level of production?

• A. Fixed costs
• B. Sunk costs
• C. Variable costs
• D. Marginal costs

Answer: (C)

Variable costs are the costs that change as output changes. They include inputs that scale with production, such as raw materials, direct labor used in making the product, and energy consumed in the production process. When you increase production, these costs rise in total; when you decrease production, they fall. In contrast, fixed costs stay the same regardless of how much you produce in the short run (like rent or certain salaries). Sunk costs are already incurred and won’t change with future production decisions. Marginal cost is the cost of producing one more unit, which is determined by variable costs but is focused on the change from one additional unit, not the overall level of production.