Which act was responsible for restructuring U.S. military and national security agencies in 1947?

The National Security Act of 1947 was a pivotal piece of legislation that fundamentally changed the structure of U.S. military and national security agencies in response to the changing geopolitical landscape following World War II. This act created the National Security Council (NSC) and established the Central Intelligence Agency (CIA), thus introducing a centralized organization for intelligence and national security policy.

Moreover, the act also combined the Department of War and the Navy into a single Department of Defense, streamlining military operations and providing a cohesive command structure. This restructuring was aimed at ensuring that the U.S. could respond effectively to the growing threats posed by the Soviet Union during the early years of the Cold War. The changes that resulted from the National Security Act set the tone for American military and foreign policy for decades to come, emphasizing a more coordinated approach to national defense and intelligence gathering.

The other options listed, while related to various aspects of military or economic regulation, do not specifically pertain to the restructuring of military and national security agencies in 1947.