Final answer:
The secret atomic energy plan developed by the United States during World War II was known as The Manhattan Project (C). It resulted in the creation of the first atomic bombs, used in Hiroshima and Nagasaki in August 1945.
Step-by-step explanation:
The name given to America's secret atomic energy plan during World War II was C) The Manhattan Project. Initiated to develop atomic weapons, the project brought together scientists from various fields and nationalities, including notable figures such as J. Robert Oppenheimer and Enrico Fermi. The Manhattan Project was a monumental undertaking that spread across multiple sites, including Los Alamos, New Mexico, and the University of Chicago. Yet it was the isolated Los Alamos laboratory that became the most iconic site associated with the project, playing a pivotal role in developing the first nuclear weapons. Funded with over $2 billion at the time, the project employed over 100,000 people and culminated in the unprecedented detonation of an atomic bomb in July 1945 during the Trinity Test at Alamogordo, New Mexico.
Led by Oppenheimer, the project's scientists succeeded in creating an atomic bomb that was later used in the bombing of Hiroshima and Nagasaki, bringing about a swift conclusion to World War II following Japan's surrender. The Manhattan Project marked a significant moment in history, ushering in the atomic age and demonstrating the devastating potential of nuclear technology.