Ordinary light is converted into plane-polarized light with the help of which of the following?

The magnetic moment of an octahedral homoleptic $Mn(II)$ complex is $5.9 \ BM$. The suitable ligand for this complex is:

Consider the following isomerism:
$i$. Ionization
$ii$. Hydrate
$iii$. Coordination
$iv$. Geometrical
$v$. Optical
Which of the above isomerisms are exhibited by $[Cr(NH_3)_2(OH)_2Cl_2]^-$?

Select the correct code regarding the total number of stereoisomers for the following compounds:
$I. [Ma_3b_2c]^{n \pm}, II. [M(AB)_3]^{n \pm}, III. [Ma_2b_2c_2]^{n \pm}$
$I - II - III$

Which of the following complexes exhibits both geometrical and optical isomerism? $(en = \text{ethylenediamine})$

What can be inferred from the magnetic moment values of the following complex species?

Complex	Magnetic Moment $(BM)$
$K_4[Mn(CN)_6]$	$2.2$
$[Fe(H_2O)_6]^{2+}$	$5.3$
$K_2[MnCl_4]$	$5.9$