Answer is: The catalyzed reaction passes through C.
A is energy of reactants.
D is energy of product of reaction.
C is activation energy with catalyst, it is lower than B and reaction with the catalyst is faster.
B is activation energy without catalyst.
Chemical reactions require heat or an input of energy to occur, this is activation energy.
By lowering activation energy, reaction need less heat. Reactions occur faster with a catalyst because they require less activation energy.
