Which of the Following Statements Is True About Sexual Behavior

Which of the following statements is true about sexual behavior among adolescents?

A) In the United States, few adolescents engage in noncoital forms of genital sexual activity.
B) The best safeguard for sexually active teens is regular use of condoms, which give some protection against pregnancy.
C) The proportion of teens who engage in sexual behavior via electronic sources declines with age because of advances in cognitive development.
D) Abstinence-only courses and virginity pledges have been shown to delay sexual activity among adolescents.