Choose the reaction(s) from the following options, for which the standard enthalpy of reaction is equal to the standard enthalpy of formation.

The standard enthalpy of formation is defined as standard enthalpy change for formation of 1 mole of a substance from its elements, present in their most stable state of aggregation.
 $\frac{3}{2}{O}_2\left(g\right)\to O_3\left(g\right);$
$\frac{1}{8}{S}_8\left(s\right)+O_2\left(g\right)\to S{O}_2\left(g\right)$ 
In the above two reactions standard enthalpy of reaction is equal to standard enthalpy of formation.