Under which condition does air get greater capacity to hold water vapour?

Correct answer: When temperature increases

Direct answer: B, when temperature increases. Air does not hold water vapour like a container with a fixed size; the amount of vapour that air can contain before becoming saturated generally increases with temperature. Warm air can therefore have a greater water-vapour capacity, while cooling reduces that capacity. If moist air cools enough to reach its dew point, condensation may begin and droplets can form. A is wrong because decreasing temperature lowers the capacity and may cause condensation. B is correct because warming increases the saturation capacity. C is wrong because dew is a result of cooling and condensation, not the cause of greater capacity. D is wrong because completed condensation means vapour has changed into liquid or solid water; it does not increase the air’s capacity. Memory cue: warm air can accommodate more vapour; cooling air moves closer to saturation.