Electrovalent compounds do not have

The electronic configurations of four elements $A, B, C, D$ are given below. Which of these elements is most likely to form an electrovalent (ionic) bond?

The compound in which the cation is isoelectronic with the anion is

Select the incorrect statement.

The most predominantly ionic compounds will be obtained from the combination of elements belonging to

Assertion $(A)$: Higher lattice enthalpy leads to greater stability of ionic compounds.
Reason $(R)$: Lattice enthalpy is a direct measure of the electrostatic forces of repulsion among the constituent ions in an ionic solid.
The correct answer is