When salt is added to water, it affects the water’s boiling and freezing points due to colligative properties. These properties depend on the number of solute particles in a solution, not their identity. The addition of salt (a solute) to water (the solvent) causes two significant changes: the boiling point increases, and the freezing point decreases. This happens because the salt ions disrupt the formation of a solid lattice structure, making it harder for water to freeze, thus lowering the freezing point (a phenomenon known as freezing point depression). Simultaneously, the presence of salt raises the boiling point because it requires additional energy (heat) to break the interactions between the water molecules and the dissolved salt ions, leading to boiling point elevation. Therefore, the correct answer is [A] Boiling point increases and freezing point decreases.