Why Did the United States Choose the Japanese Cities of Hiroshima

Why did the United States choose the Japanese cities of Hiroshima and Nagasaki as the sites for the dropping of two atomic bombs?

A) Both cities were of significant military value to the Japanese.
B) Both cities had been spared from earlier firebombing and presented virgin grounds that would show the full impact of each bomb.
C) Both cities had resisted earlier attempts by American troops to seize them by land.
D) Both cities were major cultural and political centers for the Japanese.