The solution of $II A$ group precipitate in dilute $HNO_3$ when treated with $NH_4OH$ becomes blue because of the presence of

The complex $[Cu(H_2O)_4]^{2+}$ absorbs light in the yellow region. What color will it emit as its complementary color?

Match the metal in column $I$ with the coordination compounds/enzymes in column $II$.

Column $I$ (Metals)	Column $II$ (Coordination compounds)
$a. Co$	$i. \text{Wilkinson catalyst}$
$b. Zn$	$ii. \text{Chlorophyll}$
$c. Rh$	$iii. \text{Vitamin } B_{12}$
$d. Mg$	$iv. \text{Carbonic anhydrase}$

To inhibit the growth of tumours,identify the compounds used from the following:
$(A)$ $EDTA$
$(B)$ Coordination Compounds of $Pt$
$(C)$ $D$-Penicillamine
$(D)$ $Cis-Platin$
Choose the correct answer from the option given below:

The $INCORRECT$ statement is:

$A$ white precipitate of $AgCl$ dissolves in excess of
$(I)$ $NH_{3(aq)}$
$(II)$ $Na_2S_2O_3$
$(III)$ $NaCN$