We can reject answers C) and D) :those are two famous cities in Russia, and cities would be too small to take up three-forths of Russia, the biggest country in the world.
Murmansk is also a city: in the North-West of Russia, in the Arctic Circle.
So the correct answer is: Siberia
It slowly makes the ground softer making it easier for it to dissolve
If citizens didn’t meet their duties the economy and judicial system would change terribly