Radius of Cs⁺ ion is less than that of

A) Fluoride ion 

B) Chloride ion

C) Bromide ion

We know that Cation are small in size than anion that is why ${\mathrm{Cs}}^{+}$ has smaller radius than ${\mathrm{F}}^{-},{\mathrm{Cl}}^{-},{\mathrm{Br}}^{-}$ .

Hence the required answer is D) All are correct.