What is the number of unpaired electrons in $f$ orbitals of lutetium in its $+3$ oxidation state?

Match the properties given in List-$I$ with the metals given in List-$II$:

List-$I$ (Property)	List-$II$ (Metal)
$A$. Element with maximum second ionization enthalpy	$i$. $Co$
$B$. Element with maximum third ionization enthalpy	$ii$. $Cr$
$C$. $M$ in $M(CO)_6$	$iii$. $Cu$
$D$. Element with maximum enthalpy of atomization	$iv$. $Zn$
	$v$. $Ni$

All the following statements about the transition elements are true except that:

Which of the following elements does not exhibit variable valency?

Observe the following ions: $V^{2+}, Zn^{2+}, Cu^{2+}, Fe^{2+}, Fe^{3+}, Ti^{3+}, Sc^{3+}, Ti^{4+}, Ni^{3+}, Co^{3+}, Cu^+$. How many ions in the above list have zero magnetic moment?

What is the characteristic valence shell electronic configuration of the elements of group $11$?