There are three main causes of French Revolution: political, social and economic.
Before the Revolution France was the center of autocratic monarchy where the kings declared themselves as the representatives of God.
The social condition of France was miserable. French society was divided into three classes; The Clergy, Nobles and Common people.
The Clergy was the First State, they did not pay taxes and exploited common people in various ways. The Nobility was the Second State, they also did not pay taxes. And the Third State was the farmers, sweepers, cobblers, etc. Their condition was miserable, but the doctors, lawyers, teachers, writers and philosophers belong to the Third State. They influenced people to Revolution.
So the correct answer is option C. The inequality between the lower classes and the ruling classes.
