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 :

Match List I with List II

Choose the correct answer from the options given below:

The number of complexes from the following with no electrons in the $$t_2$$ orbital is ______.

$$\mathrm{TiCl}_4,\left[\mathrm{MnO}_4\right]^{-},\left[\mathrm{FeO}_4\right]^{2-},\left[\mathrm{FeCl}_4\right]^{-},\left[\mathrm{CoCl}_4\right]^{2-}$$

The metal atom present in the complex MABXL (where A, B, X and L are unidentate ligands and $$\mathrm{M}$$ is metal) involves $$\mathrm{sp}^3$$ hybridization. The number of geometrical isomers exhibited by the complex is :