About three quarters of the russian people live a. on the north european plain. b. on the west siberian plain. c. along the pacific ocean. d. on the south european plain.

a. on the North European Plain

Explanation:

The population of Russia totals 140.8 million, the population density is 8.2 inhabitants per square kilometer.

The population is denser in central and central-eastern European Russia, near the Ural Mountains and southwestern Asian Russia. Most of the population, around 78%, reside in the European part of the country.

separation of church and state? not sure what you mean.