Given That O(g)+ E^- → O^-(g); ΔH = -142 KJ

Given that
O(g) + e^- → O^-(g) ; ΔH = -142 kJ
O(g) + 2e^- → O^2-(g) ; ΔH = 702 kJ
The enthalpy change for the reaction represented by the equation
O^-(g) + e^- → O^2-(g) is

A) 0 kJ.
B) -560 kJ.
C) -844 kJ.
D) 844 kJ.
E) 560 kJ.