The correct answer is Cirrus, Cumulous, Stratus. These are the three main types of clouds based on their appearance and altitude. Cirrus clouds are high-altitude clouds that are thin, wispy, and composed of ice crystals. Cumulus clouds are puffy, white clouds that usually have a flat base and are found at medium altitudes. Stratus clouds are low-altitude clouds that are flat, featureless, and cover the entire sky, often bringing drizzle or light rain.