Which of the following is not optically active?

Which one of the following pairs of isomers and types of isomerism are correctly matched?
$(i).$ $[Co(NH_3)_5(NO_2)]Cl_2$ and $[Co(NH_3)_5(ONO)]Cl_2$ .... (Linkage)
$(ii).$ $[Cu(NH_3)_4][PtCl_4]$ and $[Pt(NH_3)_4][CuCl_4]$ .... (Coordination)
$(iii).$ $[PtCl_2(NH_3)_4]Br_2$ and $[PtBr_2(NH_3)_4]Cl_2$ .... (Ionization)
Select the correct answer using the codes given below.

Identify the homoleptic complexes with an odd number of $d$ electrons in the central metal ion.
$(A) \ [FeO_4]^{2-}$
$(B) \ [Fe(CN)_6]^{3-}$
$(C) \ [Fe(CN)_5 NO]^{2-}$
$(D) \ [CoCl_4]^{2-}$
$(E) \ [Co(H_2O)_3 F_3]$
Choose the correct answer from the options given below $:$

The type of isomerism which exists between $[Pd(C_6H_5)_2(SCN)_2]$ and $[Pd(C_6H_5)_2(NCS)_2]$ is

The number of geometric isomers possible for the complex $[CoL_2 Cl_2]^{-}$ where $L = H_2NCH_2CH_2O^{-}$ is

Which of the following complex ions is not expected to absorb visible light?