Final answer:
The U.S. adopted a policy of intervention in Latin American affairs (option a), as reflected in Theodore Roosevelt's Big Stick Diplomacy and subsequent policies, where diplomacy was backed by military force and economic interventions.
Step-by-step explanation:
The U.S. role in Latin America is most accurately described by option a), which states that the U.S. adopted a policy of intervention in Latin American affairs, emphasizing diplomacy backed by military force.
This approach is encapsulated by President Theodore Roosevelt's Big Stick Diplomacy, an extension of the Monroe Doctrine, where the United States assumed the role of an 'international police power' to intervene in the region's nations to prevent European involvement, stabilize economies, and collect debts.
Military interventions and economic policies like Dollar Diplomacy have also shaped America's foreign relations with Latin American countries. In the early 20th century, Roosevelt believed that it was in the Western Hemisphere's interest to have the United States acting as a stabilizing force.
However, the application of this policy resulted in frequent military interventions. Although President Taft's Dollar Diplomacy aimed to promote economic cooperation and stability via U.S. investments, it often continued the cycle of interventionist policies, largely for the benefit of American interests.
The shift to a 'Good Neighbor Policy' in the 1930s represented a move away from direct intervention, but even then, interventionist strategies resurged during the Cold War era, particularly in places like Guatemala, reflecting a continued pattern of U.S. influence in Latin American politics and economics.