Which of the Following Teenagers Would Be LEAST Likely to Use

Which of the following teenagers would be LEAST likely to use birth control,or to use it effectively?

A) Alice, age 17, who is a reporter for her school newspaper, wants to be a journalist, and has been having sexual relations regularly with her steady boyfriend.
B) Barbara, age 13, who lives with her single mother and has had intercourse only once, and that was within the past month.
C) Claire, age 16, whose grades are above average and who has been sexually active for more than a year.
D) Sharon, age 18, who has been accepted to a highly selective university.