If C(g) → C(s); ΔH = – 100 kJ/mole and ΔH_f(CO₂) = – 400 kJ/mole, then find out the value of B.E_{O = O}, if B.E_{C = O} = 600 kJ/mole.
(1) 100 kJ                 (2) 300 kJ                    (3) 500 kJ                    (4) 700 kJ