Which of the following would indicate that a chemical change might be occurring

The options are missing in the question, so I am going to answer it in a general way.

There are several indicators of chemical reactions. They are:

Gas Bubbles Appear Formation of a Precipitate Color Change Temperature Change Production of Light Volume Change Change in Smell or Taste

Depending of what kind of reaction is occurring which indicator appear. For example in combustion reactions the temperature increase because they are highly exothermic; and in electrolysis of water, bubbles of molecular oxygen and molecular hydrogen are generated.