Which of the following is a characteristic of a variable cost?

Variable costs are defined by their relationship to the level of production. They change as the quantity of output produced changes. For instance, if a business produces more items, it will incur higher variable costs due to increased expenses for materials, labor directly tied to production, and other costs that fluctuate with the production level. This characteristic is fundamental in understanding costs in microeconomics, as it helps in analyzing how costs behave as production levels vary.

The other options highlight characteristics that do not align with the fundamental nature of variable costs. For example, costs that remain constant regardless of production levels describe fixed costs. A decrease in costs as production increases does not typically characterize a variable cost, as these costs usually increase with greater output. Management salaries are generally considered fixed costs, as they do not vary directly with the number of goods produced. Thus, understanding that variable costs fluctuate with production is crucial for sound economic analysis.