What were the most likely reasons that US leaders decided to develop the atomic bomb? Select two options.

They thought they needed to develop the atomic bomb before other countries did.
They wanted to be viewed by other nations as the most powerful nation in the world.
They believed that defeating Japan with regular weapons would be too costly in time and lives.
They believed they had to develop the atomic bomb to discover all of the uses of nuclear power.
They believed that only the United States was powerful enough to possess such a fearful weapon.