Answer:
Separation of government powers
Step-by-step explanation:
Baron Montesquieu was widely known as a French philosopher. In his lifetime, he was known to have written series of socio-political work or public opinions.
However, he was famous for one of his philosophical works based on principles of separation of power in which was later incorporated in the United States constitution.
Hence, in this case, the correct answer is "Separation of government powers"