The correct answer is B) It is where horses were domesticated.
The steppes of Ukraine and southern Russia are important because it is where horses were domesticated.
Archeologists had discovered some bones in the are of the North Caspian Steppes of Ukraine and southern Russia, and had applied the radiocarbon date to horse paleontological finds. Researchers considered this region as the first where humans used horses for domestic activities. It is focused in this region because, at that time, the Urals mountains did not allow horses to move to Europe. Ancestral ancients were the ones who started with the domestication of these animals.