Russia traditionally belongs to

Most of Russia's territory is in Asia, so it meets this problem.

Most of Russia's population and economy are mainly concentrated in Europe, so it doesn't meet the question.

C. the European part of Russia has always been the political, economic and cultural center of the country, so it does not meet the problem.

D. Moscow, the capital of Russia, is located in the center of the European part, so it does not meet the problem.

So choose: a.