Answer:
Separation of powers is a political doctrine originating in the writings of Charles de Secondat, Baron de Montesquieu in The Spirit of the Laws, in which he argued for a constitutional government with three separate branches, each of which would have defined abilities to check the powers of the others.
Step-by-step explanation:
I'm not sure if it's multiple choice or write in, but Charles was the first to coin the idea, while Baron introduced it fully first.
Hope this helps and good luck! :)