Final answer:
The Great Plains region, also known as Tornado Alley, experiences about 70 percent of the world's tornadoes due to its unique climatic and geographic conditions that are conducive to tornado formation.
Step-by-step explanation:
The Great Plains region of the central United States is renowned for its extreme weather phenomena, particularly tornadoes. Known as Tornado Alley, this area is geographically positioned to foster the conditions conducive to the development of tornadoes.
The correct answer to the question 'The Great Plains region of the central United States plays host to about ______ percent of the tornadoes that occur on Earth' is A. 70 percent.
The formation of tornadoes in this region is facilitated by various climatic and geographic factors, including flat land that allows for the unhindered movement of weather systems, and the meeting of cold dry air from the Rockies with warm moist air from the Gulf of Mexico, leading to instability and storm formation.