Which one of the following alkali metals gives hydrated salts?

⇒ As we know that smaller the size of an ion is, more highly it is hydrated.

⇒ Among alkali metal ions, Li⁺ is the smallest. Therefore, it has the high charge density and high polarising power.

⇒ Li⁺ ion attracts the water molecules than any other alkali metal cation.

⇒ Thus, option (A) is correct.