Answer:
See explanation
Step-by-step explanation:
A chemical reaction is said to have occurred when there is a permanent, irreversible change in a substance.
Considering the fruit in the question, the changes in the fruit can not be reversed. Nothing can ever be done to return the fruit to its original form. This ultimately shows that a chemical reaction has taken place.
Secondly, the occurrence of a chemical reaction can be confirmed by evolution of a gas. The foul smell that filled the kitchen is the gas evolved during the chemical reaction involving the rotten fruit.