$\begin{array}{1 1} \text{(a) If $AgNO^3$ is used Cu will displace $Ag^+$ from $AgNO^{+3}$, But if $[ Ag(CN)]^{-}$ is used , it is a stable complex and displacement of $Ag^+$ ions with Cu is possible .} \\ (b) \text{If $AgNO^3$ is used Cu will displace $NO^3$ from $AgNO^{+3}$, But if $[ Ag(CN_2)]^{-}$ is used , it is an unstable complex and no such displacement of $Ag^+$ ions with Cu is possible .} \\ \text{(c) If $AgNO^3$ is used Cu will displace $Ag^+$ from $AgNO^{+3}$, But if $[ Ag(CN_2)]^{-}$ is used , it is a unstable complex and displacement of $Ag^+$ ions with Cu is possible .} \\(d)\;\text{If $AgNO^3$ is used Cu will displace $Ag^+$ from $AgNO^{+3}$, But if $[ Ag(CN_2)]^{-}$ is used , it is a stable complex and no such displacement of $Ag^+$ ions with Cu is possible } \end{array} $