Which of the following is expected to form a colourless complex?

The most abundant transition metal in the human body is

The $E^{\circ}$ value for the $Mn^{3+} / Mn^{2+}$ couple is more positive than that of $Cr^{3+} / Cr^{2+}$ or $Fe^{3+} / Fe^{2+}$ due to change of

Which of the following does not show more than one oxidation state?

The transition elements have a characteristic electronic configuration which can be represented as:

Match the following:

List-$I$ (Transition metal,$M$)	List-$II$ ($E_{M^{2+}/ M}^{\ominus}$ in $V$)
$A$. $Ni$	$I$. $-1.18$
$B$. $Mn$	$II$. $-0.91$
$C$. $Fe$	$III$. $-0.25$
$D$. $Cr$	$IV$. $-0.44$

The correct answer is