Supporters of using the atomic bomb at the end of World War II believed that:

A. Japan might win the war if the bomb was not used.
B. Americans were tired of war and the US should end it quickly.
C. Russia was developing a bomb and the US needed to use it first.
D. Japan was developing a bomb and the US needed to use it first.

Supporters of using the atomic bomb believed it would force a Japanese surrender, President Truman viewed it as a quick end to the war, and the bombings of Hiroshima and Nagasaki aimed to avoid a large-scale invasion.

Explanation:

Supporters of using the atomic bomb at the end of World War II believed that it would bring a quick end to the war by forcing a Japanese surrender. This decision was made to avoid a full-scale invasion of Japan that could result in even more casualties.

President Truman believed that the atomic bomb was an instrument of war that could immediately end the conflict.

The bombings of Hiroshima and Nagasaki were seen as a way to end the war without the need for a prolonged invasion, considering the heavy casualties expected on both sides.

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