Why was the Manhattan Project kept top secret?

Why was the Manhattan Project kept top secret?

A) The United States did not want Great Britain or France to know that it had nuclear technology.

B) No one was sure if the atom bomb would actually ever work and they didn’t want negative feedback.

C) The Allies were afraid that the technology would be stolen by spies belonging to Germany or Japan.

D) The United States was developing the technology illegally and with stolen technology and materials.