Which cloud is described as 'billowy' and low-level with flat bases?

Which cloud is described as 'billowy' and low-level with flat bases?

• A. Cirrus
• B. Nimbostratus
• C. Stratus
• D. Cumulus

Answer: (D)

Clouds are grouped by how high they form and how they look. A cloud that looks like fluffy, rounded puffs—billowy—standing low in the sky with flat bases is a cumulus cloud. They form when warm air rises ( convection ); as the air cools, water vapor condenses into these distinct, cotton‑ball shapes with a relatively level bottom where condensation begins. This characteristic puffiness at low altitude is what sets cumulus apart from the others: cirrus are high and wispy, stratus form broad, flat sheets that blanket the sky, and nimbostratus are dark, rain‑laden layers. So the description matches cumulus best.

Clouds are grouped by how high they form and how they look. A cloud that looks like fluffy, rounded puffs—billowy—standing low in the sky with flat bases is a cumulus cloud. They form when warm air rises ( convection ); as the air cools, water vapor condenses into these distinct, cotton‑ball shapes with a relatively level bottom where condensation begins. This characteristic puffiness at low altitude is what sets cumulus apart from the others: cirrus are high and wispy, stratus form broad, flat sheets that blanket the sky, and nimbostratus are dark, rain‑laden layers. So the description matches cumulus best.