Which of the following reaction involves the liberation of energy?

$\left(1\right) \mathrm{Na}\left(\mathrm{s}\right)\stackrel{\stackrel{\text{ Sublimation }}{\mathrm{I}}}{\to }\mathrm{Na}\left(\mathrm{g}\right)\stackrel{\stackrel{\text{ Ionization }}{\mathrm{II}}}{\to }{\mathrm{Na}}^{+}\left(\mathrm{g}\right)$

I & II are endothermic

$\left(2\right) {\mathrm{Cl}}_2\left(\mathrm{g}\right)\stackrel{\frac{\text{ Bond dissociation energy }}{\mathrm{III}}}{\to }2\mathrm{Cl}\left(\mathrm{g}\right)$

III is endothermic

$\left(3\right) {\mathrm{Na}}^{+}\left(\mathrm{g}\right)+{\mathrm{Cl}}^{-}\left(\mathrm{g}\right)\underset{\mathrm{IV}}{\overset{\mathrm{L}.\mathrm{E}}{\to }}\mathrm{NaCl}\left(\mathrm{s}\right)$

IV is exothermic, lattice enthalpy is the energy released when gaseous cation and anion combine to form one mole of ionic crystal