The correct answer is Russia. Russia is the largest country in the world by geographical area, covering 17,098,246 square kilometers (6,601,669 sq mi). It is located in Eastern Europe and Northern Asia. Russia shares land borders with 14 countries, more than any other country in the world. These countries are Norway, Finland, Estonia, Latvia, Lithuania, Poland, Belarus, Ukraine, Georgia, Azerbaijan, Kazakhstan, China, and Mongolia. Russia also has maritime borders with Japan and the United States.
Vatican City is the smallest country in the world by geographical area, covering only 0.44 square kilometers (0.17 sq mi). It is located within the city of Rome, Italy. Vatican City is an independent city-state that is ruled by the Pope.
Australia is the sixth-largest country in the world by geographical area, covering 7,692,024 square kilometers (2,969,907 sq mi). It is located in Oceania. Australia is the only country that occupies a whole continent.
The United States is the third-largest country in the world by geographical area, covering 9,833,520 square kilometers (3,796,742 sq mi). It is located in North America. The United States is a federal republic composed of 50 states, a federal district, five major self-governing territories, and various possessions.