Final answer:
The rate of change of pressure with respect to temperature (dP/dT) is higher in the solid/liquid to gas transition.
Step-by-step explanation:
The difference between dP/dT (the rate of change of pressure with respect to temperature) in the transition from solid to liquid and from solid/liquid to gas is that it is higher in the solid/liquid to gas transition. In the solid to liquid transition, the volume of the substance does not significantly change, resulting in a smaller change in pressure compared to the solid/liquid to gas transition, where there is a significant increase in volume. Thus, option b) dP/dT is higher in the solid/liquid to gas transition is the correct answer.