Which of the following statements about the american soldiers who served in vietnam is correct?
a. most americans serving in vietnam were drafted.
b. most of the soldiers came from working-class backgrounds.
c. a high percentage of college students was drafted.
d. the average age of the soldiers was twenty-one.

the answer is b.

The Vietnam War lasted from 1955 till 1975 and resulted in a diminished reputation of the United States in the world. The system of drafting soldiers came from the Selective Training and Service Act of 1940 which resulted in 80 percent of soldiers coming from poor working class.  

Question:  Which of the following statements about the American soldiers who served in Vietnam is correct?

B. Most of the soldiers came from working-class backgrounds.