As the activity level increases within the relevant range, per-unit variable costs will usually O A. decrease O B. remain the same O C. vary randomly D. increase Operating income alone does not indicate how efficiently a segment is using its assets. True False Which of the following is an example of a cost that does not change in total over wide ranges of volume or activity? O A. the company president's salary O B. cloth used to make shirts C. bottles used in a beverage company O D. hourly wages for production line workers