Answer:
The French enlightenment thinker Montesquieu argued for - Separation of Powers.
Montesquieu developed the theory of separation of powers, in which he argued for the division of royal power in three branches: the executive power, the legislative power, and the judicial power.
This is the power divison that has become the norm in many countries around the world.
Louis XVI was unpopular with many French people, because he - Opposed political reforms.
Louis XVI was a very unpopular monarch because he ruled in a period when France was in a difficult economic situation, and he opposed the proposals of the people to solve the crisis.
The American Revolution influenced the French Revolution, because it showed the French people that - Kings can be overthrown.
The American Revolution was a great inspiration to the French Revolution because the American Revolution was the actually the first successful major revolution of the Modern era.
The French Revolution was, however, much more violent, and far less successful.