下列热化学方程式正确的是

A．2SO2+O22SO3；DH =－196．6 kJ·mol^-1

B．H2 (g)+1/2O2 (g) = H2O(l)；DH =－285．8 kJ·mol^-1

C．2H2 (g)+O2 (g) = 2H2O(l)；DH =－571．6 kJ

D．C(s)+O2 (g) = CO2 (g)；DH = +393．5 kJ·mol^-1