What does a nimbostratus cloud primarily produce?

Nimbostratus clouds are characterized by their thick, uniform layers that often cover the entire sky, creating a gray and overcast appearance. Their primary function is to produce continuous precipitation, which can manifest as rain, snow, or ice pellets, depending on atmospheric conditions. Unlike cumulus or cumulonimbus clouds, which can be associated with heavy showers or thunderstorms, nimbostratus clouds result in steadier, more prolonged precipitation that is typically lighter in intensity.

These clouds form in stable atmospheric conditions and are often associated with weather systems such as warm fronts. Their ability to produce consistent rainfall makes them significant in contributing to overall water supply, especially for agriculture and reservoirs. Thus, the defining feature of nimbostratus is their persistent precipitation, which aligns perfectly with the correct answer.