Which microstate is often described as the world's oldest surviving republic?

What is the smallest country in North America by land area? What is the second-smallest country in the world by area? What is the smallest country in the European Union by area? Which of the following countries is NOT one of the five smallest countries in the world by land area? Which of the following countries is NOT a landlocked microstate? Which country in the Persian Gulf is the smallest country in the Middle East? Which country is an archipelago of 115 islands in the Indian Ocean? What is the smallest country in Central America?