The correct cell reaction for given cell is $Sn/Sn^{+2}\parallel Ag^+/Ag$

Question

$\begin{array}{1 1}(a)\;Sn+Ag^+\rightleftharpoons Sn^{+2}+Ag\\(b)\;Sn+2Ag^+\rightleftharpoons Sn^{+4}+2Ag\\(c)\;Sn^{+2}+2Ag\rightleftharpoons Sn^{+2}+2Ag\\(d)\;Sn+2Ag^+\rightleftharpoons Sn^{+2}+2Ag\end{array}$