During decomposition of an activated complex

The activated complex which is formed by the absorbing of activation energy, so its energy becomes more than that of product and reactants.

Being highly unstable (due to high enthalpy) it breaks down into stable product or products, releasing out energy making Option (i) correct.

The Gibbs free energy of the reaction becomes less than zero (<0) due to the evolution of energy on decomposition, so the stability of product or products increases.

Since all the activated complex does not form product, some of it also changes to reactant as the energy of the reactants are also less than that of the activated complex making option (iv) correct.