The diagrams illustrate the supply curves for four separate markets. In which market is the price elasticity of supply always equal to one?
- A[IMAGE:9708_s19_qp_13_p6_diagram_2]
- B[IMAGE:9708_s19_qp_13_p6_diagram_4]
- C[IMAGE:9708_s19_qp_13_p6_diagram_3]
- D[IMAGE:9708_s19_qp_13_p6_diagram_5]