In Terms of the Enthalpy of Formation, Which of the Following

In terms of the enthalpy of formation, which of the following compounds is most stable relative to its elements under standard conditions?

A) $\operatorname{PbBr}_{2}(s) , \Delta H_{\mathrm{f}}^{\circ}=-277.4 \mathrm{~kJ} / \mathrm{mol}$
B) $\mathrm{O}_{3}(g) , \Delta H_{\mathrm{f}}^{\circ}=+142.3 \mathrm{~kJ} / \mathrm{mol}$
C) $\mathrm{SO}_{2}(g) , \Delta H_{\mathrm{f}}^{\circ}=-269.9 \mathrm{~kJ} / \mathrm{mol}$
D) $\mathrm{H}_{2} \mathrm{Se}(g) , \Delta H_{\mathrm{f}}^{\circ}=+29.7 \mathrm{~kJ} / \mathrm{mol}$
E) $\mathrm{ICl}(g) , \Delta H_{\mathrm{f}}^{\circ}=+17.8 \mathrm{~kJ} / \mathrm{mol}$