Which of the following atoms has the minimum covalent radius?

Which of the following represents the correct order of ionic radii?

Given below are two statements:
Statement $I$: The metallic radius of $Na$ is $1.86 \ \mathring{A}$ and the ionic radius of $Na^{+}$ is lesser than $1.86 \ \mathring{A}$.
Statement $II$: Ions are always smaller in size than the corresponding elements.
In the light of the above statements,choose the correct answer from the options given below:

Consider the following species: $N^{3-}, O^{2-}, F^{-}, Na^{+}, Mg^{2+}$ and $Al^{3+}$
$(a)$ What is common in them?
$(b)$ Arrange them in the order of increasing ionic radii.

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

The correct order of increasing radius of the elements $Si$,$Al$,$Na$ and $P$ is