问题详情

The author mentions the Balkans in the passage in order to explain why ______.
A．Indo-European languages were slow to spread in Old Europe
B．the inhabitants of Old Europe were not able to prevent Indo-European incursions
C．the use of the Old European script. declined
D．the Old European culture survived for a time after the Indo-European incursions请帮忙给出正确答案和分析，谢谢！