Final answer:
Clustering of hydrophobic molecules increases the system entropy by increasing the number of available microstates and allowing for greater freedom of motion.
Step-by-step explanation:
A disordered system has a greater number of possible microstates than does an ordered system, so it has a higher entropy. This is most clearly seen in the entropy changes that accompany phase transitions, such as solid to liquid or liquid to gas. For hydrophobic molecules, clustering together increases the entropy of the system because it allows the molecules to have more freedom of motion and occupy a greater number of available microstates. As a result, the overall entropy of the system increases.