uclaptEl 204011o20Theory.pdf 17. Which of the following statements is true regarding fixed and variable costs? a. Both costs are constant when considered on a per-unit basis. b. Both costs are constant when considered on a total basis. c. Fixed costs are fixed in total, and variable costs are fixed per unit d. Variable costs are fixed in total, and fixed costs vary in total. 18. Which of the following graphs illustrates the behavior of a total variable cost? Graph 1 Graph 2 Total Units Produced Totel Units Produced Greph 3 Graph 4 Total Units Produced Totol Units Produced a. Graph 2 b. Graph 3 c. Graph 4 d. Graph 1