The best answer is B.
The Warsaw pact is the name commonly given to the treaty between Albania, Bulgaria, Czechoslovakia, East Germany, Hungary, Poland, Romania and the Soviet Union which was signed in Poland in 1955 and was officially called The Treaty of friendship, Co-operation and Mutual Assistance. It was called the Warsaw pact because it was signed in Warsaw.
It was a response to the formation (by western allies) of the North Atlantic Treaty Organization (NATO). West Germany was allowed to join NATO and was allowed to re- militarize and thus the Soviets saw this as a potential threat.
I believe the answer is: D. There are three economic classes: the rich, the poor, and the middle class.
The separation between these classes is based on their ownership of wealth&resources. The poor are those who barely have enough resources to keep living,
The middle class are those who can comfortably fulfil their basic needs while having a little bit of surplus that they can put into saving , while the Rich are those who had abundance of wealth & resources, to the point where they would not able to spend it in their lifetime.