Answer:
Nationalism and imperialism encouraged each European nation to pursue its own interests and compete for power. ... The alliance system pulled one nation after another into the conflict.
Explanation:
Rivers often act as really effective and accessible trade routes, so the historian could use this map to analyse trade routes between Early River Valley Civilizations.
Hope this helps :))
Definitely C which is Russia
Korea and Vietnam had ongoing wars where the USSR and the US were directly involved.
However Cuba was also a nation of interest since the USSR was stationing Nuclear weapons and supplies there, which would lead to the Bay of Pigs invasion and the Cuban Missile Crisis.
