The catalyst does not alter the DG (change in Gibbs free energy also called Delta G ()), as the energy of reactant and product remains the same in the presence or absence of a catalyst so, the net change or difference of their energy remains the same.

Thus making option (ii) incorrect.

One can observe from the graph given below that a catalyst catalyzes the forward and the backward reaction to the same extent.

Thus making option (i) correct.

Catalyst provides an alternative path with the lower activation energy for a reaction and does not change the equilibrium constant of a reaction.

Thus making option (iii) and option (iv) correct.