Question 17 (0.5 points) Variable cost: A) decreases on a per unit basis as the number of units produced increases. B) remains constant on a per unit basis as the number of units produced increases. C) increases on a per unit basis as the number of units produced increases. D) remains the same in total as production increases. Question 18(0.5 points) Within the relevant range, the difference between variable costs and fixed costs is: Question 18 ( 0.5 points) Within the relevant range, the difference between variable costs and fixed costs is: A) both total variable costs and total fixed costs are constant. B) both total variable costs and total fixed costs fluctuate. C) variable costs per unit are constant and fixed costs per unit fluctuate. D) variable costs per unit fluctuate and fixed costs per unit remain constant