${\wedge }_m\&{\wedge }_m^0$ of a strong electrolyte are related by ${\wedge }_m={\wedge }_m^0-A\sqrt{c}$. Which one of the following electrolytes as same A as that of MgCl₂ in water.

MgCl₂ is 1:2 type (Mg²⁺ and 2Cl^-)

NaCl is 1:1 type (Na⁺ and Cl^-)

KNO₃ is 1:1 type (K⁺ and ${\mathrm{NO}}_3^{-}$)

CaBr₂ is 1:2 type (Ca²⁺ and 2Br^-)

MgSO₄ is 1:1 type (Mg²⁺ and $S{O}_4^{2-}$)