18. Suppose we observe that the revenue a music store receives from CD sales does not change when the price of CDs Is increased. What can we conclude? a] The demand for CDs is perfectly clastic. b] The price elasticity of demand for CDs is zero. c) The demand for CDs is perfectly inelastic. dj The price elasticity of demand for CDs is one. e) The price elasticity of demand for CDs is infinite. 19. Suppose the price elasticity of supply for shampoo is -0.7. If the price of shampoo increases by York, what would we expect to happen to the quantity of shampoo supplied? ") Increase by 27% bj Increase by 14% cj Increase by 13% d) Decrease by 13% e) Decrease by 27%% For Questions 20 - 23, refer to the graph below. * 20. In the graph above, which line represents a perfectly elastic supply curve? a) Line A bj Line B (] Line C dj Line D el Line E 21 In the graph above, which line represents a relatively, but not perfectly, Inelastic supply curve? "] Line A bj Line B (] Line C S dj Line D e) Line E 22. In the graph above, which line represents a perfectly inelastic supply curve? a) Line A bj Line B c) Line C dj Line D of Line E 23. In the graph above, which line represents a relatively, but not perfectly, clastic supply curve? a) Line A bj Line B c) Line C d] Line D e) Line E