Question

the enlightenment thinker baron de montesquieu came up with the idea of
the natural rights of all people.
using a revolution to obtain citizens rights.
the separation of the governments powers.
a social contract between government and people.

Explanation:

Baron de Montesquieu is known for the idea of separation of government powers (legislative, executive, judicial). Natural rights are associated with Locke, social contract with Rousseau, and revolution for rights is more linked to revolutionary thinkers, not Montesquieu.

Answer:

the separation of the government’s powers.