In the following reaction which element is oxidized ?

$Zn\left(s\right)+2H^{\oplus }\left(aq\right)⟶{Zn}^{2+}\left(aq\right)+H_2\left(g\right)$

The correct option is A $Zn$
$Zn\left(s\right)+2H^{\oplus }\left(aq\right)⟶{Zn}^{2+}\left(aq\right)+H_2\left(g\right)$
0 +1 +2 0
$Zn$ is oxidised to ${Zn}^{2+}$ and therefore, $H^{\oplus }$ is the oxidising agent.
$H^{\oplus }$ is reduced to $H_2$ and therefore, $Zn$ is the reducing agent.