Difficulties in Mexico in the Early 20th Century Affected the U.S

Difficulties in Mexico in the early 20th century affected the U.S. by .

A) interfering with trade relations.
B) encouraging massive migration of Mexicans across the border.
C) providing an investment opportunity for U.S. corporations.
D) provoking a full-fledged shooting war between Mexico and the United States.
E) None of these choices are correct.