American History help plz!

Question

One of the main reasons that the United States enters the war is?

A. oil supplies are cut off from America

B. the death of Americans when the ocean liner Lusitania is sunk

C. the bombing of New York

D. the sinking of the Titanic

Answer 1

reason for US entering WWI is B, sinking of a civilian ocean liner

Also the Zimmerman telegram where Germany promised to help Mexico get back

the Southwestern states in return for entering the war against America.

B is best answer though.