Answer : The correct answer is a) an exothermic reaction that releases energy.
Combustion reaction is generally referred as burning or when hydrocarbon reaction with oxygen to produce carbon dioxide and water . Combustion reaction releases energy. Example :
CH₄ + O₂ → CO₂ + H₂O + Energy or heat .
The reaction which releases energy or heat are known as Exothermic reactions .
Since it says hot dogs and hamburgers are cooked means they are undergoing combustion chemical reaction and so they are exothermic reactions. So option a) an exothermic reaction which releases energy is correct .