The correct answer is D (defeated soldier). After a local or tribal war, defeated soldiers were sold into enslavement. What it suggests, is that, slavery had been present in Africa before the Europeans went there. Though it is different than what we usually generalize as "Slavery". Slavery after a tribal war was considered better than European slavery.
The Czar’s autocratic policies toward the people led to social unrest because the people, especially the "common folk" or peasants were granted practically no rights and there was no democratic process--meaning that they became upset when they were unable to further their lives either socially or economically.
Mountains made it hard to find flat land.
