Answer:
B. Asia and eastern Europe
Step-by-step explanation:
Geographically speaking, Asia and Europe are actually one continent, Eurasia, as they lie on the same tectonic plate. Because of several human factors though, it has been decided that they are politically split into two separate continents. The reason for the split have been mostly culture, race, and religion.
The majority of the border between Asia and Europe is made out of the Ural Mountains. These mountains are making a border between the eastern part of Europe and the western part of Asia.
Apart from splitting Europe and Asia as separate continents, the Ural Mountains are also splitting the biggest country in the world, Russia, into two separate continents, with the majority being in Asia, and the smaller part being in Europe.