The feeling of heaviness in air just before rain may be linked with which condition?

Correct answer: High humidity and air close to saturation

Answer: A. Before or during a rain-producing situation, the air may contain a large amount of water vapour and may be close to saturation. High relative humidity reduces the rate at which sweat and other surface water evaporate, so the body’s normal cooling process becomes less effective. This can make the air feel heavy, damp, or uncomfortable. A is correct because high humidity and near-saturation explain the sensation in physical terms, although a feeling alone cannot measure humidity exactly. B is wrong because dry air usually allows faster evaporation and does not normally produce a humid, heavy feeling. C is wrong because zero water vapour would mean no atmospheric moisture. D is wrong because polar ice is not the general cause of pre-rain heaviness. Memory cue: “heavy air” usually points to moisture and weak evaporation, not greater air weight.