What happens to the boiling point of a liquid when external pressure decreases?
Decreasing external pressure reduces the energy needed for molecules to escape into the vapor phase, lowering the boiling point, as seen in high-altitude cooking. As per NCERT, applying relevant law/formula with correct units and sign convention leads to It decreases. This satisfies dimensional consistency and physical conditions given, so option B is scientifically correct.
Ref: NCBI Bookshelf, Ideal Gas Law: P1V1/T1 = P2V2/T2.
