Question

what is the major religion of russia and eastern europe

Answer 1

Christianity.

Answer 2

Orthodox Christianity

Answer 3

Russians are Orthodox Christians, and Eastern-Europeans are Catholic for the most part.

Answer 4

This used to be a couple of years ago, NOW, the primary religion, as far as the population in Eastern Europe goes (besides like Switzerland) is actually Islam.

There are many (and in fact the majority, nowadays) Arab, Muslim people.

Answer 5

Well, they want you to enter "Christianity" since that is the "official religion of Russia and (even of) Europe.

Answer 6

So just Christianity is your answer.