On a Phase Diagram,the Critical Pressure Is ________

Multiple Choice

On a phase diagram,the critical pressure is ________.

A) the pressure required to melt a solid
B) the pressure below which a substance is a solid at all temperatures
C) the pressure above which a substance is a liquid at all temperatures
D) the pressure at which a liquid changes to a gas
E) the pressure required to liquefy a gas at its critical temperature