Liquids, Solids, and Phase Transitions
A phase diagram illustrates the physical state of a substance with respect to the temperature and the pressure of the surroundings. The points plotted to draw the phase diagram are derived experimentally, and are usually plotted with temperature on the x-axis and pressure on the y-axis. A typical phase diagram is shown below in Figure-1.
The segment XZ in the phase diagram given in the passage represents the equilibrium between:
A Gas and liquid B Liquid and solid C Solid and gas D Gas and plasma