For condensation, air must reach which condition?

Correct answer: Saturation

Correct answer: A, saturation. Air becomes saturated when it contains the maximum water vapour it can hold at its current temperature. In practice, condensation begins when moist air reaches saturation, often because it cools to its dew point. At that stage, additional cooling or moisture may force some vapour to change into liquid droplets or ice particles. These particles can form dew, fog, clouds, or other forms of condensed water depending on the location and conditions. Option B is wrong because completely dry air lacks the water vapour needed for condensation. Option C is wrong because salinity describes dissolved salts in water, not the atmospheric condition required for condensation. Option D is wrong because earthquakes and seismic conditions have no necessary role in this phase change. A useful caution is that saturation is the basic condition, but condensation also needs suitable cooling or another process that allows vapour to change phase. Memory cue: no saturation, no ordinary condensation.