In the given reaction coordinate diagram:
- \( E_1 \) represents the activation energy of the forward reaction.
- \( E_2 \) represents the activation energy of the reverse reaction.
- The total energy for the forward reaction is \( E_1 + E_2 \), and the product is more stable than the reactant as indicated by the lower position of the product compared to the reactant on the energy scale.
Thus, the correct option is option (4).