What defines a tornado?

A tornado is specifically defined as a violent, rotating column of air that develops from a cumulonimbus cloud and extends to the ground. This definition highlights the critical components that characterize a tornado: the violent nature of the wind, the requirement of a cumulonimbus cloud (often associated with severe thunderstorms), and the necessity for the rotation to reach the ground to be classified as a tornado.

The involvement of cumulonimbus clouds is significant since these clouds are indicative of severe weather conditions, where strong updrafts can create the conditions necessary for tornado formation. The term "violent" is also essential, as it distinguishes tornadoes from other types of wind phenomena, which may not exhibit the same destructive potential. The other options either oversimplify the characteristics of a tornado or introduce irrelevant aspects that do not conform to its definition.