The bond enthalpy of the oxygen-oxygen bond in O₂ is 498 kJ/mol. Based on the enthalpy of the reaction represented above, what is the average bond enthalpy in kJ of an oxygen-oxygen bond in O₃?

a) 198 kJ/mol
b) 299 kJ/mol
c) 398 kJ/mol
d) 498 kJ/mol