已知下列反应的热化学方程式为:
①C(s)+O2(g)=CO2(g); △H1= - 393.5kJ/mol
②CH3COOH(l)+2O2(g)=2CO2(g)+2H2O(l);△H2= - 870.3kJ/mol
③H2(g)+1/2 O2(g)=H2O(l); △H3= - 285.8kJ/mol
则反应2C(s)+2H2(g)+O2(g)=CH3COOH(l)的△H为
A.+488.3kJ/mol B.-488.3 kJ/mol C.-244.15 kJ/mol D.+244.15 kJ/mol