It would best describe them as politically unstable
The voyages of Christopher Columbus led to the first lasting European contact with the Americas, inaugurating a period of European exploration, conquest, and colonization that lasted for several centuries. Columbus was not the first European explorer to reach the Americas having been preceded by the Norse expedition led by Leif Erikson in the 11th century. Leif Erikson was an Icelandic explorer considered by some as the first European to land in North America (excluding Greenland), before Columbus. There is much debate as some say that many different people, spanning centuries, set foot on the New World (as the Americas were called) before Columbus, and, of course, the ancestors of the Native Americans had already discovered it many years before.
From what I can recall, the Adams-Onis Treaty more or less gave Florida to the U.S. but it did not exactly end the Second Seminole War, which can be made obvious with the fact that there are Seminoles still living in Florida. I don't remember the Treaty having anything to do with the British since this treaty was between Spain and the U.S.
Basically, I believe the answer is B.