Answer: C. evaporation
Step-by-step explanation:
A physical change is defined as a change in which there is alteration in shape, size etc. No new substance gets formed in these reactions.
Example: evaporation as it involves change of state from liquid to gas
A chemical change is defined as a change in which a change in chemical composition takes place. A new substance is formed in these reactions.
Example: Corrosion as it leads to formation of new substances.
Explosion as it leads to release of heat.
Food spoilage as it involves chemical combination with oxygen.
Thus evaporation is a physical change.