Covalency is favoured in which of the following cases?

Which of the following is a covalent compound?

Given below are two statements:
Statement $I$: The correct order in terms of bond dissociation enthalpy is $Cl_{2} > Br_{2} > F_{2} > I_{2}$.
Statement $II$: The correct trend in the covalent character of the metal halides is $[SnCl_{4} > SnCl_{2}]$, $[PbCl_{4} > PbCl_{2}]$ and $[UF_{4} > UF_{6}]$.
In the light of the above statements, choose the correct answer from the options given below:

Which of the following substances has the least covalent character?

The covalent character of $CaCl_2, BaCl_2, SrCl_2$ and $MgCl_2$ follows the order:

According to Fajan's rule,covalent bond is favoured by