Which of the following orders is correct?

Given below are two statements:
Statement $I$: The number of pairs among $[Ti^{4+}, V^{2+}], [V^{2+}, Mn^{2+}], [Mn^{2+}, Fe^{3+}]$ and $[V^{2+}, Cr^{2+}]$ in which both ions are coloured is $3$.
Statement $II$: The number of pairs among $[La^{3+}, Yb^{2+}], [Lu^{3+}, Ce^{4+}]$ and $[Ac^{3+}, Lr^{3+}]$ ions in which both are diamagnetic is $3$.
In the light of the above statements, choose the correct option from the options given below:

Which of the comparison regarding $Zn, Cd, Hg$ is/are incorrect?
$(I)$ $ZnCl_2$ is ionic whereas $CdCl_2$ and $HgCl_2$ are covalent
$(II)$ $Zn$ and $Cd$ dissolve in dilute acid $(HCl)$ liberating $H_2$ but $Hg$ cannot
$(III)$ $Zn$ and $Cd$ form white ppt. of $Zn(OH)_2$ and $Cd(OH)_2$ but $Hg$ forms coloured ppt. of $HgO$ or $Hg(OH)_2$
$(IV)$ All form $M_2^{2+}$ type ion

Match the following:

List-$I$	List-$II$
$A$. Oxidation state of $V$ in $VOCl_2$	$I$. $0$
$B$. Number of unpaired electrons in $MnO_4^{2-}$ ion	$II$. $1$
$C$. Number of unpaired electrons in $[NiCl_4]^{2-}$ ion	$III$. $5$
$D$. This oxidation state is exhibited by all lanthanide ions	$IV$. $3$
	$V$. $4$
	$VI$. $2$

The correct answer is:

Match the following properties with the corresponding metals:

Property	Metal
$a$. Element with highest second ionization enthalpy $(\Delta_{i} H_2)$	$i$. $Co$
$b$. Element with highest third ionization enthalpy $(\Delta_{i} H_3)$	$ii$. $Cr$
$c$. $M$ in $[M(CO)_6]$	$iii$. $Cu$
$d$. Element with highest heat of atomization $(\Delta_{a} H)$	$iv$. $Zn$
	$v$. $Ni$

Mercury is a liquid at $0 \, ^\circ C$ because of