Answer:
The correct answer is option A, Wind Shear
Step-by-step explanation:
The tornadoes are formed from the fast rotating air which develops into a funnel shape. This is the reason why tornadoes usually occur during the thunderstorm in a cumulonimbus cloud when the wind direction and speed changes at high altitude thereby producing horizontal air swirl. Swirling air takes the shape of funnel and finally touches the base of the ground to become a tornado.