which of these was a factor in the united states entrance in world war i? a the invasion of poland b japans…

which of these was a factor in the united states entrance in world war i? a the invasion of poland b japans invasion of china c the axis threat to the panama canal d german unrestricted submarine warfare

which of these was a factor in the united states entrance in world war i? a the invasion of poland b japans invasion of china c the axis threat to the panama canal d german unrestricted submarine warfare

Answer

Brief Explanations:

The invasion of Poland and Japan's invasion of China were not the direct factors for US entry into World War I. The Axis threat to the Panama Canal was a concern in World War II. German unrestricted submarine warfare, which targeted American - flagged ships and civilian vessels, was a significant factor in the United States' decision to enter World War I.

Answer:

D. German unrestricted submarine warfare