Concept:In this system, the citizens hold the ultimate authority over the state's powers.Explanation:The phrase "powers of the state is determined by the citizens" means the people directly or indirectly decide who governs them.Monarchy places power in a king or queen.Aristocracy places power in a privileged upper class.Autocracy places power in a single ruler with absolute control.Only democracy gives sovereignty to the people through voting and participation.Answer:D. Democracy