The correct option is C Cgraphite+H2O(g)→CO2+H2(g);ΔH=−131.4 kJ
In thermodynamics, the exothermic reaction describes a reaction which releases energy from the system to its surroundings, usually in the form of heat. So for the exothermic reactions enthalpy of the reaction must be negative i.e, ΔH is negative. So the correct option is C.