Well, it's not the Ku Klux Klan, as that was a large group of people who wanted to have slaves all return to their work, I've never heard of C, and we barely touched on D in school. From what I've learned, however, the Freedmen's Bureau helped former slaves by supplying food, providing education and homes, etc.
I believe it is the last option... "Its political system cannot be easily changed.
This would be matrilineal, where the line of the mother was the relevant line, and not of the father: in order to be a king, one needed to have the royal mother and the father was irrelevant. The dynasty would be traced by the female line in this case (even if the kings were the rulers).
