(A) Hydrolith → It is CaH2. (B) Rhodamine → It belongs to the compounds having - CN group thus, it is KCNS. (C) Hair-salt → It is hydrated aluminium sulphate i.e. Al2(SO4)3.18H2O. (D) Lithopone → It is BaSO4.ZnS ∴ Hence, (b) is the correct option.