Final answer:
India has the largest democracy in the world. China is not a democracy. The United States has a presidential system.
Step-by-step explanation:
India has the largest democracy in the world. With a population of over 1.3 billion people, India is known for its vibrant and diverse democracy. The country follows a parliamentary system of government where citizens elect representatives to the Parliament.
China is not considered a democracy, as it has a single-party political system dominated by the Communist Party. The United States is a democratic country with a presidential system, while Vietnam is a socialist republic.
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