In quantitative analysis of second group in lab. $H_2S$ gas is passed in acidic medium for ppt. When $Cu^{+2}$ and $Cd^{+2}$ react with KCN, than in which of the following condition, ppt will not be formed due to relative stability :

Question

( A ) $K_3[Cu(CN)_4]$ – More stable $K_2[Cd(CN)_4]$ – Less stable
( B ) $K_3[Cu(CN)_4]$ – Less stable $K_3[Cd(CN)_4]$ – More stable
( C ) $K_2[Cu(CN)_4]$ – Less stable $K_2[Cd(CN)_4]$ – More stable
( D ) $K_2[Cu(CN)_4]$ – More stable
$K_2[Cd(CN)_4]$ – Less stable