Which one of the following has an electrovalent linkage?

Electrovalent linkage generally formed between metal and non metal atoms There are no metal atoms in ${\mathrm{CH}}_4,{\mathrm{SiCl}}_4 \mathrm{and} {\mathrm{BF}}_3$

In ${\mathrm{MgCl}}_2 \mathrm{Mg}$ is a metal and Cl is a non metal

Hence, there is an electrovalent linkage between Mg and Cl

Hint: Ionic bond is also called as electro valent bond.