I think the answer would be A
The Cold War was a period of geopolitics tension between the Soviet Union and the United States and their respective allies.
In general, the Monroe Doctrine represent a change in President Washington's foreign policy, since the Monroe Doctrine dictated that the US would treat any further attempts by Europeans to colonize the Americas as acts of aggression, and Washington was far more isolationist.
It was written by the Catholic clergyman Heinrich Kramer (under his Latinized name Henricus Institoris) and first published in the German city of Speyer in 1487.