Which of the following correctly characterizes the relevant range?

Select one:

a. The range of activity (in terms of units of production) for which cost behavior patterns are likely to be accurate

b. The range of activity (in terms of cost of production) for which variable cost behavior patterns are likely to be accurate

c. The range of activity (in terms of units of production) for which fixed cost behavior patterns are likely to be non-changing

d. The range of activity (in terms of cost of production) for which cost behavior patterns are predictable and likely to be accurate