It would be A. Land Disputes. This is because there was a fight between who could gain land and who could not. Spain wanted to keep Texas, and so that made war between the Americas and Spain. But America won, and Spain wanted a compromise. So Spain got the Southeastern part of the US that we have today. And US got the rest of the US that we have today. I hope this helps. And good luck. And I hope I was not too late. :D
