Final answer:
The two primary causes of the Cold War were the contrasting political systems and rebuilding strategies for Europe, particularly Germany and Berlin, alongside deep-seated mistrust between the Soviet Union and Western democracies. Therefore, the correct option is C.
Step-by-step explanation:
The two primary causes of the Cold War were C) differing political systems as well as disagreements over the rebuilding of Europe and Berlin, and mistrust between the Soviet Union and the Western democracies. After World War II, tensions between the United States, which favored Western-style democracies and capitalism, and the Soviet Union, which promoted Communist governments and a socialist economy, grew.
Disputes arose over how Europe, particularly Germany and its capital Berlin, should be reconstructed. These ideological differences, coupled with a history of mutual suspicion and a strategic race for influence and security, drove the US and the USSR into a prolonged period of geopolitical stalemate referred to as the Cold War. The conflict was characterized by a massive arms race, including nuclear weapons, economic aid competitions, technological and scientific rivalry, as well as proxy wars in countries such as Korea and Vietnam.