Molar conductivity ${\mathrm{A}}_{\mathrm{m}}$is defined as

where k is the conductivity and c is the molar concentration.

Molar conductivity ${\mathrm{A}}_{\mathrm{m}}$is defined as $A_m=\kappa /c$

A solution's molar conductivity can be impacted by the salt concentration or ionic strength of the solution. One mole of the electrolyte in a solution has a conductance characteristic known as molar conductivity. It is therefore not a constant.

Hence option A is correct