the statement (ii) is incorrect since the catalyst provides an alternative path of reaction with the lower activation energy, it itself does not change the activation energy.

statement (i) is correct since the function of a catalyst is to provide an alternative path for the reaction mechanism for lower activation energy.

Statement (iv) is incorrect as there is no change in the Gibbs free energy of the reaction since no alteration is done by the catalyst on the energy of reactant and product.

statement (iii) is incorrect as the catalyst provide the alternative path by forming an activated complex with lower energy it itself does not raise or lowers the activation energy of a reaction.