If sea air comes over a cool land surface and cools to dew point which event is possible?

Correct answer: Fog or dew

Direct answer: B. Sea air generally contains moisture. When it moves over a cooler land surface and cools to its dew point, the air can become saturated. Water vapour may then condense into tiny droplets. If the droplets remain suspended near the ground, fog can form; if vapour condenses directly on a sufficiently cool surface, dew can form. B is therefore the possible atmospheric event. A is wrong because volcanic eruption is a geological event unrelated to reaching the dew point. C is wrong because seismic waves result from earthquakes or other ground disturbances, not condensation. D is wrong because river erosion is caused by flowing water acting on land and is not the immediate result of air cooling to the dew point. The precise outcome depends on whether condensation occurs in the air or on the surface, so ‘fog or dew’ is appropriately phrased. Memory cue: moist air plus cooling to dew point means condensation becomes possible.