Answer:
3) Potential energy increases and average kinetic energy remains the same.
Step-by-step explanation:
Hello,
In phase transitions, when the temperature remains constant, an appreciable change in the state of the matter is done; more specifically, in the given case of water, it is changing from solid to liquid (melting). Now, the associated both potential and kinetic energy have a specific behavior in the light of the molecules distribution; in such a way, the potential energy increases as heat is being added so the molecules start moving farther. On the other hand, kinetic energy remains the same even thought they are moving but at a constant average velocity which will change when the liquid (in this case) will be completely converted.
Best regards.