Answer:
The temperature remains constant
Step-by-step explanation:
In a plot of temperature against time, it is easy to spot the points on the graph where a change of state is taking place.
During a change of state, the temperature does not not change with time. These are points that are plateaus on the temperature-time graph.
This is because, during phase change, the heat that is added is used in breaking intermolecular forces therefore a temperature change is not observed until the phase change is complete.