A solution contains ${\text{Fe}}^{2+}$, ${\text{Fe}}^{3+}$ and ${\text{I}}^{-}$ ions. It was treated with iodine at $35^{\circ }\text{C}$. $E^{\circ }$ for ${\text{Fe}}^{3+}/{\text{Fe}}^{2+}=+0.77\text{V}$ and $E^{\circ }$ for ${\text{I}}_2/2{\text{I}}^{-}=0.536\text{V}$. The favourable redox reaction is:

1. A
   ${\text{I}}^{-}$ will be oxidised to ${\text{I}}_2$
2. B
   ${\text{Fe}}^{2+}$ will be oxidised to ${\text{Fe}}^{3+}$
3. C
   ${\text{I}}_2$ will be reduced to ${\text{I}}^{-}$
4. D
   There will be no redox reaction