6. Which of the following describes the intercept in a linear cost function? a. The component of fixed costs that, within the relevant range, does vary with changes in the level of the cost driver b. The component of variable costs that, within the relevant range, does not vary with changes in the level of the cost driver c. The component of mixed costs that, within the relevant range, does not vary with changes in the level of the cost driver d. The component of fixed costs that, within the relevant range, does not vary with changes in the level of the cost driver