Which of the following compounds is expected to be colourless?

Determine whether the following statements are True $(T)$ or False $(F)$:
$(a)$ Transition elements exhibit variable oxidation states.
$(b)$ The $E^o$ values for $Mn, Zn,$ and $Ni$ are more positive than expected from the general trend.
$(c)$ Any metal exhibits its maximum high oxidation state in oxide and chloride compounds.

Match the following:

List-$I$	List-$II$
$A$. Titanium	$I$. Non-metal
$B$. Fluorine	$II$. Transition metal
$C$. Tellurium	$III$. Lanthanoid
$D$. Dysprosium	$IV$. Metalloid

Identify the general electronic configuration exhibited by the $2^{nd}$ series of transition elements.

Why are transition elements less electropositive than the metals of group-$1$ and group-$2$?

Assertion : Transition metals show variable valency.
Reason : Transition metals have a large energy difference between the $ns^2$ and $(n-1)d$ electrons.