The correct option is C Separation of Powers
"Checks and balance" is a concept set up in the United State Constitution whereby the various power of any government are divided into 30 separate branches with no one branch having all powers. This is so that no one of the 3 branches of government (executive, legislative, judicial) becomes so powerful that it becomes a virtual monarchy. It also ensures that all three will work together in relative harmony since each needs the others to perform its obligations properly.