The atomic radii of the elements are almost the same for which series?

The electronic configuration of silver atom in ground state is

Match the following aspects with the respective metal.

Aspects	Metal
$a$. The metal which reveals a maximum number of oxidation states	$i$. Scandium
$b$. The metal although placed in $3d$ block is considered not as a transition element	$ii$. Copper
$c$. The metal which does not exhibit variable oxidation states	$iii$. Manganese
$d$. The metal which in $+1$ oxidation state in aqueous solution undergoes disproportionation	$iv$. Zinc

Select the correct option.

The metal$(s)$ which does/do not form amalgam is/are

Consider the following pairs of elements and identify the pairs of elements which have nearly same atomic radius.
$I$. $Y, La$
$II$. $Zr, Hf$
$III$. $Mo, W$
$IV$. $Cr, Mo$

Among the following options,identify the element which exhibits the greatest number of oxidation states.