Which of the Following Best Describes a Step Variable-Cost Function

Multiple Choice

Which of the following best describes a step variable-cost function?

A) a step cost function in which cost remains the same over narrow ranges of the level of activity in each relevant range
B) a step cost function in which cost remains the same over narrow ranges of the level of activity outside the relevant range
C) step cost function where the cost remains the same over wide ranges of the activity in each relevant range
D) step cost function where the cost remains the same over wide ranges of the activity outside the relevant range