Which of the following square-planar complexes exhibits $cis-trans$ isomerism?

Which of the following has diamagnetic character?

$CoSO_{4}Cl \cdot 5NH_{3}$ exists in two isomeric forms '$A$' and '$B$'. Isomer '$A$' reacts with $AgNO_{3}$ to give white precipitate,but does not react with $BaCl_{2}$. Isomer '$B$' gives white precipitate with $BaCl_{2}$ but does not react with $AgNO_{3}$. Answer the following questions.
$(i)$ Identify '$A$' and '$B$' and write their structural formulas.
$(ii)$ Name the type of isomerism involved.
$(iii)$ Give the $IUPAC$ name of '$A$' and '$B$.'

Amongst the following ions,which one has the highest magnetic moment value?
$(i)$ $[Cr(H_2O)_6]^{3+}$
$(ii)$ $[Fe(H_2O)_6]^{2+}$
$(iii)$ $[Zn(H_2O)_6]^{2+}$

Which of the following complex ions has a magnetic moment same as $[Cr(H_2O)_6]^{3+}$?

Which one of the following does not exhibit geometrical isomerism?