Which of the following best explains the Missouri Compromise of 1820?

As violence against slaves increased, the government created a haven for runaway slaves in Missouri.

By admitting both a slave state and a free state, the nation's legislature hoped to keep a balance of power.

As fights about slavery increased, the legislature voted to return the right to choose whether to be a slave or free state to the states.

By creating a group of border states between the North and South, the nation's leaders hoped to avoid increasing disputes over runaway slaves.

since most of current immigration into the u.s., both legal and illegal, is coming from latin america. it would be very difficult to imagine or rationalize a country my fellow citizens are trying desperately to flee into, would pose a threat to my prosperity or freedom. since the u.s. has a long history of intervention, but no record of permanent occupation, i would not feel oppression is the main objective.  

the largest free trade nation, along with the largest gdp in the world wanting to expand it's economic policy on us, and including us, could only be positive. the u.s. government has no interest in, or way of simply forcing american culture on us. and has no track record of it. other nations that adopted american social culture, or "americanization" did so voluntarily, mainly through the choice of allowing american businesses and u.s. citizens to come into their nations, as free operatives.

the answer is a, salt plain

b or c im pretty sure

where are the answer choices