The correct answer to this open question is the following.
Although the question doesn't include options, we can say the following.
Our Senate has finally emerged from weeks of debate with a decided version of the Missouri Compromise. Among its list of provisions, all lands acquired in the Louisiana Purchase that are north of the southern border of Missouri, with the exception of Arkansas, will now be free states, where slavery was prohibited. On the other hand, the states south this border would be slavery states, where people could own slaves.
In 1820, the Missouri Compromise represented an agreement between north and southern states of the Union about the situation of the western territories recently acquired. The negotiations were based on the authorization of slavery in these territories. The decision was that Missouri was going to enter the Union as a slave state, meanwhile, Maine entered as a free state.