The answer which defines exothermic reaction is
a process in which energy is released as heat ( answer A)
<u><em>Explanation</em></u>
Exothermic reaction is a chemical reaction in which energy is released into environment in form of heat.
<u> For example of exothermic reaction</u>
Is a combustion reaction such as lighting a candle whereby oxygen react with wax to produce carbon (iV) oxide, water and heat.