Why was the u. s. finally able to gain the upper hand on japan as losses mounted up? american forces were better prepared. america was able to rebuild faster. japan had less-capable leaders. the japanese mainland was attacked.

The correct answer is B) America was able to rebuild faster.

The U.S. finally was able to gain the upper hand on Japan as losses mounted up because America was able to rebuild faster.

After the Pearl Harbor attack of December 7, 1941, in Hawaii, the United States suffered painful losses of lives and infrastructure. Many ships were destroyed and the presence of the United States Navy in the Pacific was weakened.

But the United States had the economy, the resources, and the power, and the logistics to face this complicated situation to rebuilt, prepare a good strategy and enter World War II being part of the Allied forces with Russia, France, and Great Britain.

because it took place after the war of 1812 had come to an end.