Explanation

(d)
According to Born-Haber cycle the enthalpy of formation $(\mathrm{\Delta}H_{f})$ of an ionic compound may be given as
$\mathrm{\Delta}H_{f} = S + \frac{1}{2}D + I + E + U$
Where, I = ionisation energy
S = sublimation energy
E = electron affinity
D = dissociation energy
U = lattice energy of compound
Born-Haber cycle is used to determine the lattice energy of the compound. It also may be used to calculate electron affinity of an element.