Answer:
A. The temperature and pressure above which a supercritical fluid exist.
Explanation:
The physical states of a substance under different temperature and pressure conditions is represented by a phase diagram. In this diagram, normally the pressure is represented on the y-axis while the temperature is present on the x-axis. There is a point on this diagram called the critical point, beyond this point the liquid and the gaseous phase become indistinguishable. When the substance surpasses the critical point, it is referred as a supercritical fluid.
From the above description, all the options other than A is false.