Why was the United States building more bombs after WWII even though it wasn't offically at war?

The explicit reason was to swiftly end the war with Japan. Ever since America dropped a second atomic bomb on Nagasaki, But even as Truman issued his statement, a second atomic attack was already in the works and Nagasaki Wasn't the Original Target

Explanation:

hope this helps

i would say your answer is a)

sorry if im wrong