During which stage of a thunderstorm does rain begin to fall?
a. the development stage
c. the mature stage
b. the precipitation stage
d. the waxing stage

The correct answer is the mature stage.

Explanation:

The majority of the thunderstorms get produced by a cycle that comprises three phases: the cumulus stage, the mature stage, and the dissipating stage. In the mature stage, the cumulus cloud turns very big, and the water in it turns heavy and large. The drops of rain begin to fall via the cloud when the elevating air can no more hold them.  

In the meantime, the cool dry air begins to enter the cloud. As the cool air is denser in comparison to the warm air, it begins to incline in the cloud called downdraft. The downdraft makes the heavy water to fall downward, resulting in rain.