The correct answer is b-forming neighborhood militilas
Answer: Kievan Rus is also called as the land of Rus. It is located in Russia.
Explanation:
The internal cause of the down fall: The empire weaken by the collapse of the commercial trade with the Byzantine empire and this lead to major economic crises in 12th century.
The various rival regional powers were influencing the working of the state.
The external cause of the down fall: The Mongol invasion in 1240s caused the complete fall of the state.
The Toltecs were responsible for establishing a variety of the basics that the rest of their Central Mexicans would follow. However, the Toltecs could not establish the major cities and trading centers that people like the Teotihuacanos and the Aztecs would later establish.