The correct answer is letter (D) Tornado. If a rotating cyclone spawns a smaller rotation, called a vortex, it may extend down to the ground as a (D) Tornado. A vortex is a region in a fluid where the flow is rotating around a certain axis line. The axis line can either be straight or curved, depends on the direction. Vortices can be observed from ocean whirlpools, Tornadoes, etc.
