The correct answer is the United Nations. As of now however, there are 193 countries, which is a lot more than in 1945 when there were 51 member states. The territory in New York where the headquarters are are considered to be international territory. It is the most famous international organization in the world.
The Machu Picchu is one of those listed in the World Heritage Sites and is considered as one of the most important archeological sites on Earth. What makes this important is that it is the living evidence of the Inca Empire's achievement and power. The answer to this would be option D.
German Aggression, Depression, and Conflict of Ideologies.
Hope this helped!
STSN