What is the $SI$ unit of conductivity?

The variation of molar conductivity with concentration of an electrolyte $X$ in aqueous solution is shown in the given figure.
The electrolyte $X$ is :

An electrolyte of a polymer-salt complex of poly(ethylene oxide)-LiCF$_{3}$SO$_{3}$ is shaped into a free standing circular film of $20 \ mm$ diameter and a thickness of $20 \ \mu m$. When it is sandwiched between $2$ stainless steel circular electrodes of the same diameter, this cell exhibits a conductance of $\frac{314}{5} \ S$. What is the specific conductivity of the electrolyte?

$A$ conductivity cell containing $0.001 \ M$ $AgNO_3$ solution develops resistance $6530 \ \Omega$ at $25 \ ^{\circ}C$. Calculate the electrical conductivity of the solution at the same temperature if the cell constant is $0.653 \ cm^{-1}$.

The limiting molar conductivities of the given electrolytes at $298 \ K$ follow the order: $\lambda^{\circ}_{(K^{+})} = 73.5, \lambda^{\circ}_{(Cl^{-})} = 76.3, \lambda^{\circ}_{(Ca^{2+})} = 119.0, \lambda^{\circ}_{(SO_{4}^{2-})} = 160.0 \ S \ cm^{2} \ mol^{-1}$.

Which solution of $NaNO_3$ will have maximum specific conductance in $N$?