Which of the following explains why some congressmen objected to Missouri joining the Union?

(1 point)
• The area was beyond the Mississippi River, too far away from Washington, DC.
• Missouri did not have enough people to become a state.
• Missouri wanted to join the Union as a slave state, upsetting the balance in Congress.
• No other states were ready to join as non-slave states.

The correct explanation is: Missouri wanted to join the Union as a slave state, upsetting the balance in Congress.