Which will have the maximum value of electron affinity $O^x,{\mathrm{O}}^y,{\mathrm{O}}^z[x,y$ and $$$z$ respectively are $0,-1$  and $-2]$?

Being a neutral atom, oxygen will have higher electron affinity as there is electrostatic repulsion between additional electron and negative ion in case of ${\mathrm{O}}^{-}$ and ${\mathrm{O}}^{2-}$. 

So option A is correct.