For a concentrated solution of a weak electrolyte (Kₑᵩ = equilibrium constant) A₂B₃ of concentration ‘c’, the degree of dissociation 'α' is
1. (Kₑᵩ/108c⁴)¹/⁵
2. (Kₑᵩ/6c⁵)¹/⁵
3. (Kₑᵩ/5c⁴)¹/⁵
4. (Kₑᵩ/25c²)¹/⁵