Select the strongest reducing agent from the given electrode potential.

• A

  ${\mathrm{E}}_{{\mathrm{Zn}}^{2+}/\mathrm{Zn}}^{\mathrm{o}}$

• B

  ${\mathrm{E}}_{{\mathrm{Cr}}^{3+}/\mathrm{Cr}}^{\mathrm{o}}$

• C

  ${\mathrm{E}}_{{\mathrm{H}}^{+}/{\mathrm{H}}_2}^{\mathrm{o}}$

• D

  ${\mathrm{E}}_{{\mathrm{Fe}}^{3+}/{\mathrm{Fe}}^{2+}}^{\mathrm{o}}$