In which of the following is the electron gain enthalpy of elements correctly arranged?

What is the correct order of electron affinity for the elements of the oxygen group in the periodic table?

The formation of the oxide ion $O_{(g)}^{2-}$ requires first an exothermic and then an endothermic step as shown below. This is because
$O_{(g)} + e^{-} \rightarrow O_{(g)}^{-}; \Delta H^{o} = -142 \ kJ \ mol^{-1}$
$O_{(g)}^{-} + e^{-} \rightarrow O_{(g)}^{2-}; \Delta H^{o} = 844 \ kJ \ mol^{-1}$

The set containing the elements with positive electron gain enthalpies is

In which of the following processes is energy absorbed?

Which will have the maximum value of electron affinity among $O^x, O^y$ and $O^z$ ($x, y$ and $z$ are $0, -1$ and $-2$ respectively)?