Q. Which country was the first to exit the European Union?
Answer: United Kingdom
Notes: The United Kingdom was the first country to leave the European Union, a process commonly referred to as Brexit. This historic decision was made following a referendum held on June 23, 2016, where 51.9% of voters chose to leave. The formal exit occurred on January 31, 2020, marking a significant moment in European political history and reshaping the relationship between the UK and EU.