A galvanic cell which makes use of the following reaction at 298K. $Cr_2O_7^{2-}+14H^++6Fe^{2+}\rightarrow 2Cr^{3+}+6Fe^{3+}+7H_2O$.Given : $E^{\large\circ}(Cr_2O_7^{2-},H^+,Cr^{3+}|Pt)=1.33V;E^{\large\circ}(Fe^{3+},Fe^{2+}|Pt)=0.77V$.Reducing $[Fe^{3+}]$ to 0.50M keeping all other concentrations at unity,the emf of the cell will be changed by

Question

$\begin{array}{1 1}-0.059V\\-0.0178V\\0.059V\\0.0178V\end{array}$