For the reaction given below,

$2\mathrm{Na}\left(\mathrm{s}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right)⟶2\mathrm{NaH}\left(\mathrm{s}\right)$

choose the correct option from the following.

$2\mathrm{Na}\left(\mathrm{s}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right)\stackrel{\mathrm{\Delta }}{⟶}2\stackrel{+1}{\mathrm{Na}} \stackrel{-1}{\mathrm{H}}\left(\mathrm{s}\right)$

Depending upon the increase in oxidation state Na is oxidized and decrease in oxidation state of H from 0 to -1 shows its reduction.