The correct option is C 693.8 kJ mol−1 energy is evolved in the reaction
we know :
ΔH=Hproducts−Hreactant
A negative value of ΔH shows that HP<HR , i.e.,enthalpy of two moles of ZnO is less than the enthalpy of two moles of zinc and one mole of oxygen by 693.8 kJ.
As HP<HR, the reaction is exothermic and 693.8 kJmol−1 of energy is evolved in the reaction.