The total number of reagents from those given below that can convert nitrobenzene into aniline is . (Integer answer)

I) $\mathrm{Sn}-\mathrm{HCl}$

II) $\mathrm{Sn}-{\mathrm{NH}}_4\mathrm{OH}$

III) $\text{Fe-HCl}$

IV) $\mathrm{Zn}-\mathrm{HCl}$

V) ${\mathrm{H}}_2-\mathrm{Pd}$

VI) Raney Nickel

Nitrobenzene is converted into aniline with help of reducing agents like $\mathrm{Sn}-\mathrm{HCl}$, $\mathrm{Fe}-\mathrm{HCl},\mathrm{Zn}-\mathrm{HCl},{\mathrm{H}}_2-\mathrm{Pd}$ and Raney nickel.

All the above reagents give the same reaction as,

$\mathrm{Ph}-{\mathrm{NO}}_2+$ Reagent $\to \mathrm{Ph}-{\mathrm{NH}}_2$

Hence, the correct answer is 5 .