Correct option is C
Sodium (Na) has the maximum atomic radius among the elements listed. Atomic radius generally decreases across a period from left to right on the periodic table due to the increasing nuclear charge, which pulls the electrons closer to the nucleus. Sodium is located further to the left in the periodic table compared to phosphorus (P), sulfur (S), and chlorine (Cl), hence it has a larger atomic radius.
Na (227pm) > P (195pm) > S (180pm) > Cl (175pm)
