Textbook problem 4C.15

[Naibe Reynoso 2C]

Can someone explain why the answer is C and not D for this problem? The heat capacities matched both graphs, however, I do not see how c shows the enthalpy of fusion and vaporization. Could someone explain the difference?

[Rachel 1J]

D cannot be the correct answer because there is no changes in temperature when a substance is changing phases. Those horizontal, flat lines on the heating curve represent the changing of phases of the substance. D indicates that during phase changes, temperature is still increasing, which isn't correct.