Use the quotation to answer the question.
Finally, you have broader considerations that might follow what you would call the “falling domino” principle. You have a row of dominoes set up, you knock over the first one, and what will happen to the last one is the certainty that it will go over very quickly. So you could have a beginning of a disintegration that would have the most profound influences. –U.S. President Dwight D. Eisenhower
What was one result from the theory discussed in the accompanying quotation?
China invaded North Korea.
The U.S. occupied Cambodia during the Vietnam War.
The U.S. supported the noncommunist government of South Vietnam.
North Vietnam installed communist governments in Cambodia and Laos.