Out of the following,which one has the highest value of covalent character?

Given below are two statements: One is labelled as Assertion $A$ and the other is labelled as Reason $R.$
Assertion $A :$ Lithium halides are somewhat covalent in nature.
Reason $R :$ Lithium possesses high polarization capability.
In the light of the above statements,choose the most appropriate answer from the options given below:

If the ionic character of $Na^{+}$ and $S^{2-}$ ions is greater than that of $Mg^{2+}$ and $Cl^{-}$ ions,which of the following will be the least soluble in water?

State $Fajans$ rules for the partial covalent character of ionic bonds.

What is the bonding nature in $LiCl$ bond?

Describe the law of Fajan's rule.