Answer : The correct option is, Activation energy.
Explanation :
Activation energy : It is defined as the energy required to initiate the reaction is known as activation energy. Or, the amount of energy required to reach the transition state.
Or we can say that, the minimum amount of energy that is absorbed by the reactant molecules so that their energy becomes equal to the threshold energy.
As per given information, we conclude that when heat applied to the reactants then it causes a faster chemical reaction. The heat is considered as activation energy. As we know that by providing heat the collision between the molecules of reactants increases and it causes the faster chemical reaction.
Hence, the correct option is, Activation energy.
