Concept:Dew is produced when water vapour in the air condenses on cool surfaces.
Explanation:During the early hours of the morning, grass loses heat rapidly by radiation.
This cooling causes the air in contact with the grass to fall below its dew point.
At the dew point, the air is saturated with water vapour.
The excess water vapour then condenses into tiny liquid droplets on the grass blades.
These small droplets of water are called dew.
Hail is frozen rain falling from clouds.
Fog and mist are collections of water droplets suspended in the air, not on the grass.
Therefore, the correct answer is dew.
Answer:B. Dew