The formulation of the oxide ion $O^{2-} (g)$ requires first an exothermic and then an endothermic step as shown below <br> $O(g) + e^-O^-(g) \Delta H^{\circ} = -142 \; kJ\; mol^{-1}$ <br> $O^-(g) + e^-O^{2-} (g) \Delta H^{\circ} = 844\;kJ\; mol^{-1}$

Question

( A ) $O^-$ ion has comparatively large size than oxygen atom
( B ) Oxygen has high electron affinity
( C ) Oxygen is more electronegative
( D ) $O^-$ ion will tend to resist the addition of another electron