Correct answer choice is :
C) Maine was added to the United States as a free state.
Explanation:
On March 3, 1820, Congress declared a bill allowing Missouri statehood as a slave state under the circumstance that slavery was to be always banned in the rest of the Louisiana Purchase north of the 36th parallel, which runs roughly along the southern border of Missouri. The mission of the Missouri Compromise was to keep a stability between the number of slave states and the number of free states in the Union. It let Missouri enter as a slave state at the same time Maine enrolled as a free state, thus preserving asymmetry in numbers of free and slave states.
