Which of the following will have a standard oxidation potential less than $SHE$?

Reduction of species is dependent on its reduction potential value.

For the given cell reaction $Fe^{2+}_{(aq)} + Ag^{+}_{(aq)} \rightarrow Fe^{3+}_{(aq)} + Ag_{(s)}$,the standard cell potential is:
Given:
$Ag^{+} + e^{-} \rightarrow Ag \quad E^0 = x \ V$
$Fe^{2+} + 2e^{-} \rightarrow Fe \quad E^0 = y \ V$
$Fe^{3+} + 3e^{-} \rightarrow Fe \quad E^0 = z \ V$

Given below are half-cell reactions:
$MnO_{4}^{-} + 8H^{+} + 5e^{-} \rightarrow Mn^{2+} + 4H_{2}O$,
$E^{o}_{MnO_{4}^{-} / Mn^{2+}} = +1.510 \, V$
$\frac{1}{2} O_{2} + 2H^{+} + 2e^{-} \rightarrow H_{2}O$,
$E^{o}_{O_{2} / H_{2}O} = +1.223 \, V$
Will the permanganate ion,$MnO_{4}^{-}$,liberate $O_{2}$ from water in the presence of an acid?

The standard reduction potentials of $Cu^{2+}$,$Zn^{2+}$,$Sn^{2+}$ and $Ag^{+}$ are $0.34 \ V$,$-0.76 \ V$,$-0.14 \ V$ and $0.80 \ V$ respectively. Which of the following solutions can be stored in the given vessel without any reaction occurring (under standard conditions)?

The reduction potential values are given below. Which is the strongest reducing agent? $Al^{3+}/Al = -1.67 \, V, Mg^{2+}/Mg = -2.34 \, V, Cu^{2+}/Cu = +0.34 \, V, I_2/2I^- = +0.53 \, V$