Which of the following is a low spin complex?

Which of the following compounds is brown coloured?

Write down the $IUPAC$ name for each of the following complexes and indicate the oxidation state,electronic configuration,and coordination number. Also,give the stereochemistry and magnetic moment of the complex:
$(i)$ $K[Cr(H_2O)_2(C_2O_4)_2] \cdot 3H_2O$
$(ii)$ $[Co(NH_3)_5Cl]Cl_2$
$(iii)$ $CrCl_3(py)_3$
$(iv)$ $Cs[FeCl_4]$
$(v)$ $K_4[Mn(CN)_6]$

Given below are two statements:
Statement $I$ : Dimethyl glyoxime forms a six-membered covalent chelate when treated with $NiCl_2$ solution in presence of $NH_4OH$.
Statement $II$ : Prussian blue precipitate contains iron both in $(+2)$ and $(+3)$ oxidation states.
In the light of the above statements,choose the most appropriate answer from the options given below:

$CuSO_{4(aq)} + 4NH_3 \rightarrow X,$ then $X$ is

Match the following:

Column-$1$ (Reaction)	Column-$2$ (Main product)
$A$. $4FeCl_3 + 3K_4[Fe(CN)_6] \rightarrow$	$I$. $Fe_4[Fe(CN)_6]_3$
$B$. $ZnCl_2 + 4NaOH \rightarrow$	$V$. $Na_2ZnO_2$
$C$. $2FeCl_3 + H_2S \rightarrow$	$II$. $FeCl_2$