As the total volume of activity changes Multiple Choice the total of variable costs stays the same. the total of fixed costs changes variable costs per unit change. fixed costs per unit change. Prev 4 of 15 Next> The term "relevant range" is used to describe Multiple Choice the range of activity where costs will always fluctuate the range of activity where fixed costs change proportionately as activity changes. the range of activity where total variable cost remains unchanged as activity changes. the range of activity where a particular.relationship between fixed and variable costs stays valid