. In which of these equations, does the heat of reaction represent standard enthalpy of formation of the product?
1. N2O4(g) + 2NO2(g)
II. C(g) + O2(g) + CO2(g)
5
III. N2(g) + O2(g) → N20 (9)
2.
IV. C(g) + O2(g) → CO(g)

A: III
B: II, III
C: II, III, IV
D: I, II, III, IV