Electron affinity is positive for

• A. \[O(g)+{{e}^{-}}\to {{O}^{-}}(g)\]
• B. \[S(g)+{{e}^{-}}\to {{S}^{-}}(g)\]
• C. \[{{O}^{+}}(g)+{{e}^{~}}^{-}\to O(g)\]
• D. \[{{O}^{-}}(g)+{{e}^{-}}\to {{O}^{2-}}(g)\]