The correct answer is - Russia.
Most of the eastern boundary of Europe passes through the territory of Russia. More specifically, the eastern border of Europe is marked by the Ural Mountain Range, which stretches from the Arctic circle and down to the Caspian Sea. It is a natural border that people have been using it for thousands of years. Even though Europe and Asia are geologically the same continent, people have divided it in two parts and used the Ural Mountains as a border because it has represented the border between people with different culture, race, way of life, language families...
