Which sulfide is soluble in $(NH_4)_2CO_3$?

Which of the following sulfides is yellow in color?

$A$ solution containing a group $IV$ cation gives a precipitate on passing $H_2S$ gas. $A$ solution of this precipitate in dilute $HCl$ produces a white precipitate with $NaOH$ solution and a bluish-white precipitate with basic potassium ferrocyanide. The cation is:

The correct option$(s)$ to distinguish nitrate salts of $Mn^{2+}$ and $Cu^{2+}$ taken separately is (are):
$(A)$ $Mn^{2+}$ shows the characteristic green colour in the flame test
$(B)$ Only $Cu^{2+}$ shows the formation of precipitate by passing $H_2S$ in acidic medium
$(C)$ Only $Mn^{2+}$ shows the formation of precipitate by passing $H_2S$ in faintly basic medium
$(D)$ $Cu^{2+}/Cu$ has higher reduction potential than $Mn^{2+}/Mn$ (measured under similar conditions)

Which of the following is not correctly matched?

Which of these reactions is correct?