Heat occurs when:
B) Matter changes state from a vapor to a liquid.
Explanation:
When matter changes its state from a vapor (gas) to a liquid, heat is released in the process. This release of heat is known as heat of condensation. An example of this is when steam (vapor) from boiling water comes into contact with a cool surface, such as a lid or a cold spoon, and condenses back into liquid water. In this process, heat is transferred from the steam to the cool surface, leading to the formation of liquid water droplets.
This change of state from vapor to liquid is a physical change that involves the release of heat energy. Heat is being transferred from the vapor to the surroundings during this process.
