The correct option is A Te2− > I− > Cl− > Ar+
Size ∝ number of shells.
Number of shells present in Te2− & I− (five shells) are more than that in Cl− & Ar+ (three shells).
Te2− & I− are isoelectronic.
Since, size ∝ negative charge.
So, Te2− > I− and Cl− > Ar+.
Combining both factors, overall order is:
Te2− > I− > Cl− > Ar+