The correct option is B The extension of slavery into the Northwest Territory
The Missouri Compromise did not extend the practice of slavery into the
Northwest Territory. The Northwest Ordinance of 1787 had barred slavery
from that territory. The Missouri Compromise dealt with the admission of
Maine and Missouri into the Union, with Missouri as a slave state and
Maine as a free state. It also banned slavery from the area of the
Louisiana Purchase north of the 36° 30' north latitude line.