What type of clouds are primarily associated with thunderstorm activity?

Cumulus clouds are the correct choice when it comes to clouds predominantly associated with thunderstorm activity. These clouds typically appear as fluffy, white, and puffy formations, often indicative of rising moist air. When conditions are right, especially with sufficient instability in the atmosphere, cumulus clouds can develop into larger cumulonimbus clouds, which are directly associated with thunderstorms.

Cumulonimbus clouds are characterized by their towering, anvil-shaped tops and can produce severe weather phenomena such as heavy rain, lightning, hail, and strong winds. The initial development of a thunderstorm usually begins with the growth of cumulus clouds as they gather moisture and energy from warm surface air.

In contrast, other cloud types mentioned do not generally indicate thunderstorm activity. Nimbostratus clouds are associated with continuous, steady precipitation rather than the storms described. Cirrostratus clouds are high-altitude clouds that often produce a halo effect around the sun or moon but do not spawn thunderstorms. Stratocumulus clouds typically consist of low, lumpy clouds that do not have the vertical development necessary for thunderstorms. Therefore, the association of cumulus clouds with the formation and development of thunderstorms is crucial to understanding weather patterns and forecasting severe weather events.