The molar conductivities of NH⁺₄ ion and Cl⁻ ion are 73.5 mho cm² mol⁻¹ and 76.2 mho cm² mol⁻¹ respectively. The specific conductivity of
0.1 M NH₄Cl is 1.22 ×10⁻² mho cm⁻¹. What is the dissociation constant of NH₄Cl?

A. 0.8
B. 0.27
C. 0.81
D. 0.35