The correct answer is:
B. The United States is a representative democracy; ancient Greece was a direct democracy.
Explanation:
Although the Founding Fathers of the United States were deeply inspired by the ancient Greece's form of government, the main difference between both democracies is that the United States has a representative democracy; also known as democratic republic, American citizens elect their representatives (President, Senators, members of the Congress) to represent the citizens' interests and protect their rights in the government, while the ancient Greece had a direct democracy, citizens would gather together on assemblies and were allow to vote on any government issue, like passing laws or making decisions.