Which one of the following alkaline earth metal sulphates has its hydration enthalpy greater than its lattice enthalpy?

Beryllium sulphate (BeSO4) has its hydration enthalpy greater than its lattice enthalpy. Hence, it is highly soluble in water. On moving down the group, the solubility of alkaline earth metal sulphates decreases. Thus, barium sulphate and radium sulphate are practically insoluble. Hence, option B is correct.