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.

• A
  $A$
• B
  $B$
• C
  $C$
• D
  $D$