Answer:
Option C, It is the difference between reactant energy and maximum energy.
Step-by-step explanation:
The activation energy is the minimum energy required to initiate any chemical process or reaction. This energy along with reactant energy is required to break down the chemical bonds with in the reactants and start the chemical reaction.
The maximum energy is the energy contained with in the activated complex formed during the process of any chemical reaction.
Basically, this activation energy is equal to the difference of energy of the activated complex (maximum energy) and the reactant energy.
Hence, option C is correct