Baron de Montesquieu is most closely associated with which idea?

Separation of powers

B. A government's powers should be separated among different branches of government.

Explanation:

The notion of separating political powers became first found in Baron d Montesquieu's Spirit of Laws a document dating back to 1748,

"There can be no liberty where the legislative and executive powers are united in the same person or body of magistrates ... [or] if the power of judging is not separated from the legislative and executive powers."

He then would create the theory for the creation of a "tripartite system", advocating the distribution of powers.

He refers to political powers as legislative and judiciary branches to the executive, limiting thus the monarchs.

At the time he wrote, Kings concentrated the power in themselves and with Montesquieu's contributions, people came to regulate the monarchs these were called aristocrats.

Aristocracies were the first forms of government that began to astray from a single ruler having the absolute and authoritarian rule, often given by birth and claiming a divine right-origin.