Respuesta :
Based on the information given, the U.S. involvement in World War II was caused by the Japanese bombing of Pearl Harbor on December 7, 1941. This is the best answer since the next day after the bombing, the U.S. declared war on Japan and then three days later declared war on Germany. All other events did not directly impact the United States which is why they did not immediately enter the war. The bombing was a direct hit on the United States and forced them into the war. Germany declaring war on the United States as due in part to the pact signed by Germany, Japan, and Soviet Union on September 27, 1940.
I believe the answer is: The United States entered World War II because Japan attacked its Navy.
Prior to this attack, united states adopt a neutralist approach in its foreign policy, which make them avoid any intervention toward the affairs of other nations as much as possible. When Japanese army attacked the pearl harbour, the support to enter world war II was given by the majority of people.