A part of the periodic table is given below. The elements lithium, carbon, sulphur and argon have been placed in their correct position. The positions of the other elements are represented by hypothetical letters.

$1$	$2$	$13$	$14$	$15$	$16$	$17$	$18$
Lithium	$\mathrm{A}$	$\mathrm{B}$	Carbon	$\mathrm{C}$	$\mathrm{D}$	$\mathrm{E}$	$\mathrm{F}$
$\mathrm{I}$			$\mathrm{G}$		Sulphur	$\mathrm{L}$	Argon
$\mathrm{J}$		$\mathrm{H}$				$\mathrm{M}$
$\mathrm{K}$						$\mathrm{N}$

With reference to this table, answer the following:

Arrange $\mathrm{C}, \mathrm{D}$ and $\mathrm{E}$ in the increasing order of their atomic radii.