The correct answer is B.the practice of absolute monarchy
Absolute monarchy was a political system that the revolutionist wanted to overthrow in order to establish a democratic Republic with a new Constitution. This is a political cause in terms that it tends to change the political system itself. While the other options were also causes of the French Revolution, in fact, they are more related to other factors than being strictly political. The division of the people in three estates is more a social factor than a political one, the Enlightenment corresponds more to a cultural factor, and the increase of taxes is an economic cause of the French Revolution.
