At $298 \ K$ the molar conductivities at infinite dilution $(\Lambda_m^{\circ})$ of $NH_4Cl, KOH$ and $KCl$ are $152.8, 272.6$ and $149.8 \ S \ cm^2 \ mol^{-1}$ respectively. The $\Lambda_m^{\circ}$ of $NH_4OH$ in $S \ cm^2 \ mol^{-1}$ and $\%$ dissociation of $0.01 \ M \ NH_4OH$ with $\Lambda_m = 25.1 \ S \ cm^2 \ mol^{-1}$ at the same temperature are

• A
  $275.6, 0.91$
• B
  $275.6, 9.1$
• C
  $266.6, 9.6$
• D
  $30, 84$