In which of the following reactions, the heat liberated is known as 'heat of combustion'.
A. `H_((aq))^(+)+OH_((aq))^(-)rarrH_(2)O_((l))+"heat"`
B. `C("graphite")+(1)/(2)O_(2(g))rarrCO_((g))+"heat"`
C. `CH_(4(g))+2O_(2(g))rarrCO_(2(g))+2H_(2)O_((l))+"heat"`
D. `H_(2)SO_(4(aq))+H_(2)O_((l))rarrH_(2)SO_(4(aq))+"heat"`
