Supporters of using the atomio bomb at the end of World Viex I believed that

Japan might win the war the bomb was not used,

Americans were tired of war and the US should end a quickly

Russia was developing a bomb and the US needed to use a free,

Japan was developing a bomb and the US needed to use it forek,

A. Japan might win the war if the bomb was not used

Explanation:

since these are supporters of the atomic bomb we're talking about here, they were in support of using the atomic bomb. they believed without it, americans couldn't fight back against the japanese and that japan would win the war. so these supporters believed for the united states to win instead, the atomic bomb had to be used