Which of the following equations corresponds to the enthalpy of combustion at `298K`?

Options

A. (a) `C_(2)H_(6)(g) +7//2O_(2)(g) rarr 2CO_(2)(g) +3H_(2)O(g)`
B. (b) `2C_(2)H_(6)(g)+7O_(2)(g)rarr 4CO_(2)(g)+6H_(2)O(g)`
C. (c) `C_(2)H_(6)(g) + 7//2O_(2)(g) rarr 2CO_(2)(g)+3H_(2)O(l)`
D. (d) `2C_(2)H_(6)(g)+7O_(2)(g)rarr 4CO_(2)(g)+6H_(2)O(l)`

Explanation

Combustion of one mole of reactants gives products in standard state or most stable state.