Was the second bomb in Japan necessary

The world may never know. For his part, Truman doesn't seem to have wavered in his conviction that the attacks were justified—though he ruled out future bomb attacks without his express order the day after Nagasaki. "It was a terrible decision

Explanation:

Depending on your point of view, the second bomb on japan might have played a major role in ending the war, by showing the prowess the US had in the war, though also killing many, many civilians.

Explanation:

The moral debate on wether or not the US should have dropped the bombs on Japan is an on going debate, and is very dependent on ones worldview. In a perfect world, no, we would not have dropped the bombs, but the decision was made, and the dropping of the bombs ended the war.

yup! you are correct it is b.