The correct answer is - Different parts of the region were the most influenced by cultures that had easiest access to them.
Most of Eastern Europe is relatively flat lowland, and it also borders Asia, as well as being part of the great Eurasian steppes. Because of this, in Eastern Europe it was very common that new people with new cultures from Asia were coming, invading, integrating, and that had left a huge mark on the development and culture of the people living in this part of the continent. Starting with the Scythians, Sarmatians, Avars, Huns, Tatars, Khazars, Kumans, Mongols, Bulgars, Magyars, Szekeli, all came from Asia, and all had big influence on the region in whichever aspect do we look at it.
