The correct answer is (a) wave the fumes toward your nose with your hand. If you smell the chemicals directly, it could be harmful too your health, especially if they are strong. Also remember to <em>never </em>smell chemicals unless you are being told to do so.
Because they're not confident enough to confirm it's indeed true but they will support it for they believe it's correct.
I believe it is because, Lead has a higher boiling point than zinc. by the time Lead melts and becomes a liquid, the temperature is way higher than the boiling point of Zinc therefore, Zinc becomes a gas.