The complexes $[Co(NH_3)_6][Cr(C_2O_4)_3]$ and $[Cr(NH_3)_6][Co(C_2O_4)_3]$ exhibit which type of isomerism?

Which of the following complexes will show coordination isomerism?
$A. [Ag(NH_3)_2][Ag(CN)_2]$
$B. [Co(NH_3)_6][Cr(CN)_6]$
$C. [Co(NH_3)_6][Co(CN)_6]$
$D. [Fe(NH_3)_6][Co(CN)_6]$
$E. [Co(NH_3)_6][Fe(CN)_6]$
Choose the correct answer from the options given below:

Which of the following complex ions will have a magnetic moment of $2.82 \ BM$?

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

The complex that shows Facial - Meridional isomerism is

Number of stereoisomers exhibited by $[Co(en)_{2} Cl_{2}]^{+}$ is