The answer is C) It prohibited slavery in most of the former Louisiana Territory except for Missouri.
Why is it C)? well its C) because the Missouri Compromise (1820) <span>prohibited slavery in most of the former Louisiana Territory except for Missouri.</span> Specifically, it prohibited slavery above 36°30'N. This was meant to prevent slavery from being an issue as new states was added, but this would not be the case.
Louisiana purchase of 1803 doubled the size of the united State give the country complete control of the port of new Orleans, and provided territory for westward expansion.