Respuesta :

adumaru
An exothermic reaction is a chemical reaction that releases energy by light or heat. It is the opposite of an endothermic reaction. Expressed in a chemical equation: reactants → products + energy.
This is how I remember it...
Ex: Exits
Exothermic: Releases energy

Your answer would be: C, a reaction that releases energy into the environment.

If you ever need help on endothermic....
En: Absorbs or enter
Endothermic: Absorbs energy

HOPE THIS HELPS! ^_^