Final answer:
A tyrant is synonymous with a dictator who exercises absolute power, distinguishing them from kings, presidents, or monarchs; this is exemplified by leaders like Kim Jong-Un contrasted with democratic leaders like Barack Obama.
Step-by-step explanation:
The term tyrant is another term for a dictator, not a king, president, or monarch, making option D the correct answer. A dictator holds complete and absolute authority over a government and its population and often rises to power through means such as economic or military might, and maintains power through tactics like intimidation and brutality. For instance, contemporary leaders considered dictators include individuals such as Kim Jong-Un, whereas elected officials like Barack Obama or David Cameron cannot be categorized as dictators since they operate within a democratic governance structure.
After the American Revolution, revolutionaries turned to republicanism, which implies a form of government without a hereditary ruling class, governed by representatives chosen by the people. Thus, a republic is the antithesis of a monarchy, where an individual monarch rules, often for life or until abdication, whether through hereditary succession or divine appointment.