Which group elements have the smallest atomic radii in their respective periods?

From the given set of species,point out the species from each set having the least atomic radius.
$A. F^{-}, Na^{+}, Mg^{+2}$
$B. Ni, Cu, Zn$
$C. N^{-3}, Cs^{+}, H^{-}$
$D. Li, He, Be^{+2}$

What is the method to estimate the volume of an individual atom?

If four different elements $A, B, C$ and $D$ have electronic configurations as $A = [Ne] 3s^2 3p^4$,$B = [Ne] 3s^2 3p^5$,$C = [Ar] 3d^{10} 4s^2 4p^4$ and $D = [Ar] 3d^{10} 4s^2 4p^5$,identify the element with the largest atomic radius.

The correct order of atomic radii of $B, Be, N$ and $C$ is

In period $4$ of the periodic table, the elements with the highest and lowest atomic radii are respectively: