Catherine the Great (C) transformed the residence in St. Petersburg, the Hermitage, into a center of culture, paintings, and performing arts. It still stands as a great museum of art today.
They achieved weakening the Nazis and helping to boost morale of the allied powers.
Answer: Mongols did not necessarily need to expand their territories as much as they did. The pull factor for Mongol imperialism is directly related to the push factors. They may have included climactic and geographic issues impacting the nomadic tribes but most likely were due to the Mongols being enthusiastically militaristic.
C would be the best choice in my opinion. Hope this helps!