$($b$)1,2,4-$Triazole reacts with $Fe(Il)$ salts in chloroform to form a stable, $1-$

dimensional coordination polymer $A$ in which the $Fe(II)$ centres are

octahedrally coordinated. Its temperature$-$dependent optical properties are

shown below. When $A$ is treated with stoichiometric amounts of water,

compound $B$ can be isolated.

Figure: UV$-$Vis spectra of compound A $($left$)$ and structure of compound B $($right$).$

$($i$)$ Explain the UV$-$vis spectra of $A.$

$($ii$)$ Sketch the expected temperature$-$dependence of the magnetic moments of

A and $B.$

$($iii$)$ Draw and explain the expected temperature$-$dependence of the M$$ssbauer

spectrum of compound $B.$