Which of the Following Statements About Secondary Schools Is True

Which of the following statements about secondary schools is true?

A) In the developing world, rates of enrollment in secondary schools have not changed much in a century.
B) Almost all American 17- and 18-year-olds are enrolled in school.
C) Many poorer families in developing countries no longer need their adolescents to work.
D) In most developed countries, more boys than girls are enrolled in secondary school.