In which condition can more water droplets be seen on grass in the morning?

Correct answer: Night was cool, clear and calm

Correct answer: A. During a clear night, the ground and grass can lose heat by radiation and cool substantially. If the night is calm, there is little mixing with warmer air above, so the grass surface can reach its dew point. Water vapour in the air then condenses directly on the cool grass as liquid droplets called dew. A cloudy sky can reduce this cooling, while strong wind mixes the near-surface air and often prevents the surface from becoming as cold. B is therefore unfavourable because it combines heat and wind. C supplies very little moisture for dew. D describes a warm surface, which is less likely to reach the dew point quickly. Cue: cool surface plus moist, calm night produces dew.