In paragraph 3, why does the author discuss languages spoken in the region spanning from Eastern Europe to the western borders of Mongolia? A. To emphasize the frequency with which Indo-European languages changed as a result of the mobile nature of pastoralism B. To indicate one method linguists use to determine that inhabitants of the Don and Dnieper river area had taken up stock breeding C. To provide evidence that Indo-European languages have their roots in what is now Turkey D. To provide evidence that pastoralist societies can exercise cultural influence over a large area