5 nations claimed territory
Its just the atomic bombing of Hiroshima
The correct answer is D) Monroe Doctrine.
The Monroe Doctrine was based around the idea of there being different "spheres of influence." This concept resulted in America influencing the entire Western hemisphere (including the Latin American countries/territories) while also being isolated from European affairs. The goal of this doctrine was to stop European influence from happening in the Western Hemisphere.
The reason why the Spanish-American War deals with this concept is because after this concept was implemented, the Spanish still controlled Cuba. Cuba, which is located in the Western Hemisphere, was supposed to be under the influence of the United States. This explains why the US got involved in this war.