Final answer:
Montesquieu's idea that a government should be divided into three equal parts, each having a check and balance against one another, is called C. Separation of Powers.
Step-by-step explanation:
Montesquieu's idea that a government should be divided into three equal parts, each having a check and balance against one another, is called C. Separation of Powers.
According to Montesquieu, the executive, legislative, and judicial functions of government should be assigned to distinctly different bodies to avoid concentration of power and abuse of authority. This idea was influential in the development of democratic systems, including the United States.