For a dilute solution of a strong electrolyte,the variation of molar conductivity with concentration is given by

Question

$\begin{array}{1 1}\Lambda_m=\Lambda^{\infty}_m+bc\\\Lambda_m=\Lambda^{\infty}_m-bc\\\Lambda_m=\Lambda^{\infty}_m+b\sqrt c\\\Lambda_m=\Lambda^{\infty}_m-b\sqrt c\end{array} $