Final answer:
The correct clockwise arrangement of phases on a P-V diagram is: compressed liquid region, saturated liquid, critical point, constant pressure lines, superheated vapor region, saturated vapor.
Step-by-step explanation:
To arrange the phases of a substance in a clockwise order based on the P-V (pressure-volume) diagram, we need to understand the layout of a typical phase diagram. Starting from a high pressure and low temperature point (usually the upper left of the diagram) and moving clockwise we would encounter the following regions and points: compressed liquid region, saturated liquid, the critical point, constant pressure lines (which are horizontal in the diagram), superheated vapor region, and finally saturated vapor. Therefore, the correct sequence is option (a): Compressed liquid region, Saturated liquid, Critical point, Constant pressure lines, Superheated vapor region, Saturated vapor.