Answer :
The statement that explains why the U.S. got involved in the Vietnam War was D. It raised officials' alarm about the global spread of communism.
Why did the U.S. get involved in Vietnam?
The U.S. was quite worried about the spread of Communism around the globe and so acted to stop it. This was the main basis of the Civil War.
In order to prevent Communism from spreading in Southeast Asia, the U.S. got involved in Vietnam which then became part of the Cold War.
In conclusion, option D is correct.
Find out more on the Cold War at https://brainly.com/question/856013.