Answer
(a) Distillation.
(b) Magnetic separation.
(c) Filtration.
Work Step by Step
(a) Salt + Water is a homogeneous mixture. Since salt has a much higher boiling point that water, you can use distillation to separate them.
(b) Since a magnet attracts iron, but doesn't attract lead, you can use this method to separate these two.
(c) If we add water to a mixture of elemental sulfur and sugar, we can remove the sulfur using filtration, because it is not soluble in water.