Consider the following complexes (A) $$\left[\mathrm{CoCl}\left(\mathrm{NH}_3\right)_5\right]^{2+}$$, (B) $$\left[\mathrm{Co}(\mathrm{CN})_6\right]^{3-}$$, (C) $$\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_5\left(\mathrm{H}_2 \mathrm{O}\right)\right]^{3+}$$, (D) $$\left[\mathrm{Cu}\left(\mathrm{H}_2 \mathrm{O}\right)_4\right]^{2+}$$ The correct order of A, B, C and D in terms of wavenumber of light absorbed is :