Answer: The correct answer is Option 1.
Step-by-step explanation:
For the given options:
Option 1: During a phase change
Whenever phase change occurs, the temperature remains constant because the heat is used to overcome the intermolecular forces between the particles.
Option 2: During a pressure change
As we know pressure is directly related to the temperature. So, if the pressure is increased, the temperature will also increase and vice-versa.
Option 3: During a change in kinetic energy
Kinetic energy is directly related to the temperature of a substance. So, if the kinetic energy is increased, the temperature will also increase and vice-versa.
Option 4: During a change in molecular velocity
Molecular velocity is directly related to the temperature of a substance. So, if the molecular velocity is increased, the temperature will also increase and vice-versa.
Hence, the correct answer is Option 1.