What type of costs do not change with the level of output?

Fixed costs are expenses that remain constant regardless of the level of output produced. These costs are incurred even when production is zero and do not vary with the volume of goods or services produced. Examples include rent, salaries of permanent staff, and equipment leases.

In contrast, variable costs fluctuate in direct relation to output levels. For instance, costs for raw materials or hourly labor will increase as production ramps up. Average cost, which represents the cost per unit produced, changes as the output level changes as well, incorporating both fixed and variable costs into the calculation. Total costs, which comprise both fixed and variable costs, also change with output since they include costs that vary with production.

Therefore, fixed costs are the only type of costs that do not change with the level of output, making them the correct choice.