Which of the following best explains the difference between an absolute monarchy and a republic?

AAn absolute monarchy is ruled by a single individual; a republic elects representatives to make decisions.
BAn absolute monarchy is run by many wealthy citizens; a republic is operated by a wealthy individual.
CAn absolute monarchy has a two-party system; a republic has a single-party system.
DAn absolute monarchy is ruled by a small group of citizens; a republic concentrates power in one individual.