because kiev was a major center of slavic population, kiev kept the slavs\nunder kievs powerful rule.\nfrom…

Brief Explanations:

Kiev, as a major Slavic population center, served as a unifying force. It protected the Slavs from external domination. The other options are less relevant. "Under Kiev's powerful rule" is too one - sided as the focus is on protection. "From wanting to live in any place other than Kiev" is not a main historical role. "Under the influence of the Eastern Orthodox Church" is a separate aspect not directly related to the population - center role in preventing domination.

Answer:

from being dominated by other groups.