The mismatched combinations are
$A.$ Chlorophyll $- Co$
$B.$ Water hardness $- EDTA$
$C.$ Photography $- [Ag(CN)_2]^-$
$D.$ Wilkinson catalyst $- [(Ph_3P)_3RhCl]$
$E.$ Chelating ligand $- D^{-}$\text{Penicillamine}
Choose the correct answer from the options given below:

Assertion: $AgCl$ dissolves in $NH_4OH$ solution.
Reason: Due to formation of a complex.

If a didentate ligand ethane-$1, 2$-diamine is progressively added in the molar ratio $en : Ni :: 1: 1, 2: 1, 3: 1$ to $[Ni(H_2O)_6]^{2+}$ aqueous solution,the following coordination entities are formed:
$I$. $[Ni(H_2O)_4en]^{2+}_{(aq)} -$ pale blue
$II$. $[Ni(H_2O)_2(en)_2]^{2+}_{(aq)} -$ blue/purple
$III$. $[Ni(en)_3]^{2+}_{(aq)} -$ violet
The wavelengths in $nm$ of light absorbed in the case of $I$ and $III$ are respectively:

In photography,sodium thiosulphate is used as:

Write the application of coordination compounds in black and white photography.

Which color of light is absorbed by an aqueous solution of $CuSO_4$?