Feudalism. Feudalism was the medieval model of government predating the birth of the modern nation-state. Feudal society is a military hierarchy in which a ruler or lord offers mounted fighters a fief (medieval beneficium), a unit of land to control in exchange for a military service.
        
             
        
        
        
Answer: B. It represents the main route for settlers moving into the Oregon Territory.
Explanation:
In the early 1800s Americans were encouraged to stretch the USA from the east coast to the west coast in what was called the Manifest destiny. The line above aided in this venture as it enabled people to reach Oregon to the west of the United States. 
Rightfully named the Oregon Trail, the line went through four states and allowed hundreds of thousands of people to move to Oregon and other areas in western USA thereby paving the way for the assimilation of those territories into the United States. 
 
        
                    
             
        
        
        
Christopher Columbus was a Spanish navigator who proposed to sail across the Atlantic to get to India for trade, accidentally discovering the Americas. He did a number of things to the indigenous peoples. He traded with them, he enslaved some, and he also mistook them for East Indians.
        
             
        
        
        
The Second Industrial Revolution, also known as the Technological Revolution, was a phase of rapid scientific discovery, standardization, mass production, and industrialization from the late 19th century into the early 20th century.
        
                    
             
        
        
        
There were many reasons. The country was in extreme poverty, there was starvation everywhere and people were dying in misery. They wanted to change the imperialistic rule and impose their own bolshevik rule. People also wanted to end their participation in the war which is one of the first things that happened after the revolution. The communists left the war before the war ended.