The following reaction takes place during electrolysis of brine

2Cl^– (aq) + 2H₂O(l) → 2OH^– (aq) + H₂(g) + Cl₂(g)

Here, chloride ionsgets oxidised to chlorine gas.

Thus, oxidation occurs and not reduction, hence option (ii) is incorrect. It is a redox reaction and not a displacement reaction,so option (iv) is also incorrect.

The ∆G^° of this reaction is +422kJ which is a positive value so option (iii) is incorrect as well.

Therefore, option (i) is the correct option.