What was one of the major motivations for initiating the Manhattan Project?

A. The United States wanted to prove its military superiority over the other countries.
B. The Allied governments feared that Germany was developing atomic weapons.
C. The United States needed a weapon to use in future wars against the USSR.
D. The Manhattan Project was only intended to develop peacetime uses for atomic energy.

The Manhattan Project was a research and development project carried out during the Second World War that produced the first nuclear weapons, led by the United States with the support of the United Kingdom and Canada. From 1942 to 1946 the project was under the direction of Major General Leslie Groves of the Army Corps of Engineers of the United States, while the nuclear physicist Robert Oppenheimer was the director of the Los Alamos Laboratory in which the nuclear bombs were designed .

Two types of atomic bombs were developed simultaneously during the war: a relatively simple ballistic-type fission weapon and a more complex implosion nuclear weapon. The fission design of the Thin Man pump proved impractical for use with plutonium, so a simpler weapon called Little Boy was developed using uranium-235, an isotope that constitutes only 0.7% of the uranium in natural state.