Consider the following $E^{\circ}$ values <br> $E^{\circ}_{Fe^{3+}/Fe^{2+}} = 0.77V$ <br> $E^{\circ}_{Sn^{2+}/Sn} = -0.14V$ <br> Under standard conditions the potential for the reaction <br> $Sn(s) + 2Fe^{3+}(aq) \to 2Fe^{2+} (aq) + Sn^{2+}(aq)$ is

Question

( A ) 0.91 V
( B ) 1.68 V
( C ) 1.40 V
( D ) 0.63 V