How were the atomic bombs created in New Mexico used during WWII?

a.
They were tested at White Sands, but the technology was never used.
b.
They were dropped on the German cities of Munich and Berlin.
c.
They were extensively by both British and American Air Forces.
d.
They were dropped on the Japanese cities of Hiroshima and Nagasaki.

d. They were dropped on the Japanese cities of Hiroshima and Nagasaki.