Answer: Option (a) is the correct answer.
Step-by-step explanation:
When an element or atom has the ability to attract electrons towards itself then it is known that atom is electronegative in nature.
Therefore, two atoms with different electronegativity are combined together then there will be increase in electronegativity difference of the atoms.
For example, NaCl is an ionic compound.
This is because electronegative chlorine atom will attract the valence electron of sodium atom. Due to this there will be development of partial positive charge on the cation and partial negative charge on the anion. Hence, ionic character increases.
Therefore, we can conclude that as electronegativity difference increases, the degree of ionic character increases.