16-20 please and thank you

16. A factor that causes a product cost to increase or decrease is called. a. An activity pool. b. A cost driver. C. An estimate. d. A period cost. 17. Curvilinear costs: a. Form a circle if graphed. b. Are costs outside a relevant range. C. Approximates a mixed cost, within a relevant range. d. Cannot be graphed 18. A cost that changes in direct proportion to a change in business activity level is called: a. A fixed cost. b. A variable cost. C. A direct cost. d. An indirect cost. 19. The volume of activity where an organization's expenses equal its income is called: a. A contribution margin. b. A break-even point. c. A target net profit. d. A safety margin. 20. In a make-or-buy decision, relevant costs to consider are: a. Manufacturing costs that will be saved. b. The purchase price of the units to be bought C. Opportunity costs. d. All of the above