Which among the following complexes is associated with the maximum wavelength of light absorbed?

Consider the following complexes:
$[CoCl(NH_3)_5]^{2+},$ $[Co(CN)_6]^{3-}$
$(A)$ $(B)$
$[Co(NH_3)_5(H_2O)]^{3+},$ $[Cu(H_2O)_4]^{2+}$
$(C)$ $(D)$
The correct order of $A, B, C,$ and $D$ in terms of the wavenumber of light absorbed is:

The magnitude of crystal field stabilisation energy in octahedral field depends on :
$I.$ The nature of the ligand
$II.$ The charge on the metal ion
$III.$ Whether the metal is in the first,second or third row of the transition elements

Calculate the Crystal Field Stabilization Energy $(CFSE)$ for a high-spin $d^4$ tetrahedral complex.

Which of the following complex ions absorbs the light of minimum wavelength?

How many of the following ligands are stronger than $H_2O$? $S^{2-}$,$Br^{-}$,$C_2O_4^{2-}$,$CN^{-}$,$en$,$NH_3$,$CO$,$OH^{-}$