Final answer:
Fixed costs are constant within the relevant range while the level of the associated driver varies.
Step-by-step explanation:
The costs that are constant within the relevant range while the level of the associated driver varies are fixed costs. Fixed costs are expenses that do not change regardless of the level of production or sales. Examples of fixed costs include rent, salaries, and insurance. These costs remain constant within a certain range of production, but may change if the business expands or contracts.